Why Full-Time to Part-Time 4WD conversion is POINTLESS | 4xOverland
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- Опубліковано 5 жов 2024
- The conversion from full-time 4WD to part-time 4WD is a mod based on a myth. Logically, one can save fuel and it probably does save fuel. But it is so little, that any mod to do it is pointless because the fuel savings are so small, and the cost to safety, tire wear and handling is so high that the result is a net loss.
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Andrew it's hard to do donuts and burnouts in 4wd.
put a turbo on, then it's easy hehe
Unless you were lucky enough to have the 1998 5.9L Jeep Grand Cherokee
You forgot to mention one rather important benefit of RWD over permanent 4WD - donuts. Donuts and burnouts. Both of them are utterly useless and sometimes even downright dangerous, but the childish fun is priceless.
Lets be accurate you dont build them, you watch them build it, second I just finished making my 97 FZJ80 from AWD to part time with aisin hubs and 300 m inserts mated to RCV 300M axles and a marks adaptors spool. the part time allows better mileage MUCH less wear and tear on all moving parts up front. and a birf goes unlock and roll. So your wrong homie.
Your better mileage saving will be a fraction of the cost of the conversion. I know with the FZJ you'll be looking for every bit of fuel saving, but you'd be better off with a diesel. I did enjoy the power though, but paid severely at the pump.
Yep, AWD sucks. Converted my 100 series and never looked back. I also have a 4x4 sequoia with normal 4wd. Don’t know why the hell they didn’t make it like the sequoia with coilovers.
Craig Ice kit was around $600, more power and lighter steering. Well worth it.
"Much better mileage". Please share with class what much better mileage means with 37" tires, a huge lift, and an RTT? I love your rig and am starting to enjoy exploring your channel. But c'mon, the aero load alone on your rig is like 500X whatever infinitesimal gain in consumption would be from not spinning the front drivetrain stuff. It's just not credible.
Dontwant to run the rcvs with full time it will wear them out really fast.cant wait to get some for mine
I don't like hearing anyone rant about anything except when it's you, because we share the same opinions! These are my rants too...
Hi Andrew
I developed the first part time kit in 1992 for 80 series
We did it for because we were have maintenance issues with front drive flanges cv splines and inner axle seals
Toyota upgraded these with and update in late 1994 and the problem mostly disappeared after that but the kit continued to sale .Marks 4wd copied the idea in about 1999 . Yes did a lot of dyno tests and discovered that the front half of the drive used 8 kilo watts of power so that may have given a very small fuel saving and the reason the Pajero didn’t is because the front drive train was still spinning . As a side note Toyota threatened to sue me for modifying their vehicle but backed of because the maintenance issues that the kit was developed for were true I hope this enlightens you .now sit down ,take a deep breath and have a scotch
even dyno tested the mod to prove it worked thats great!
Oh man, this bloke needs to calm down!!
I think possibly he regrets buying a vehicle without having it checkout first and needed to pick on something
To his credit he has show us the build in full even if it make him look a bit silly for not getting checked out
Great showcase for Terrain Tamer which is a good Australia business I have dealt with for many years
@@robkay9227 Even that is no guarantee, mine was check out by the same people and cost me allot. Problems after problems. $$$$$$$$
Rob Kay.the 80 series came out with a part time 4wd
I do agree. I have fitted a lot of these part time kits into the 80 and 100 series land cruises for one reason only. The repair costs to the drive train when towing large heavy loads. The landcruiser is a fantastic vehicle but the full time 4x4 is week in everyday towing and the repair costs are heavy replacing CV joints outer drive flanges,the repairs to the front diff head and transfer case on a on going basis. So a lot of customers either traded for a 70 series landcruiser or a Nissan patrol or we fitted the part time kit which made them comfortable to drive and eliminate the maintenance costs
Agree. This point was not covered in the video.
Walter Ashby the ability to engage low range on a boat ramp without braking anything is a great advantage as well.
Just generally more options!
@@ajphillipsracing or backing trailers and vans up driveways
I like my part time conversion on my 80 series. I didn't do it for increased fuel mileage. I did the conversion so i could run an automatic locker in the front axle. It was cheaper to buy the conversion kit and BOTH lockers than it was to buy one ARB locker, let alone the compressor. I like knowing that my lockers will ALWAYS work. I don't have to worry about air lines leaking or anything like that. I see no strange tire wear and the steering is a little lighter which isn't necessarily a bad thing. There's less wear and tear on front end components.I also like driving on the trails in 2wd until 4wd is needed. All i do is hit that center diff lock button and i'm ready to rock! Its just more fun!! I have had absolutely zero ill effects of doing this "mod". Each to their own!
Thanks Andrew, I was seriously considering installing a part-time kit in my 105 in the hope it would improve fuel economy. You have convinced me that I would save more money by leaving it as it is... a big, heavy, full-time 4WD. If I really want better fuel economy I should get a Jimny and camp with my hiking gear, like I did in my 20's in my 1978 Suzuki :D
I disagreed with him, read my explanation above. I had both constant & part time 4WD & kept the parts to convert it back if it was no good. I never converted my rig back because most of my driving is highway use & only need 4 WD on occasions. Not having a 2nd diff running Improved my overtaking capability out of sight, it's night & day difference & yes I drive a notable 50 km farther on (roughly depending on driving style) a tank on highway use but in the bush 4 WD or 2 WD fuel use is near on the same, that's the real story from my 1HD-FT Auto.
Andrew, I’m a truck driver here in the states, so that’s where I get my experience. Fuel consumption comes from weight first (almost entirely actually), and aerodynamics waaaaay behind. The only reason that a 4wd truck gets “worse” consumption is because of the added weight. I put worse in quotations because it’s only worse when one is ignoring capability and safety. Given the increase in capability and safety, the cost of increased fuel consumption is more than acceptable.
Love to listen to your information. I live in the states and owned a 1978 4x4 with the np203 full time transfer case. It was my dream truck and I loved how it would go on mud or snow and ice covered roads. I seldom locked it into 4 wheel lock because it seldom needed it unless I was in a rough place where I wanted to just creep along slowly. It finely wore out after 30 plus years. I was the second owner and replaced the motor once and had the transfer case chain and gears replaced due wear over many thousands of miles. I now have a 1994 ford f150 4x4 with rear wheel drive only unless you lock it in. It is the most helpless truck I have ever seen. I was so used to just being able to drive not worry if it was a little mud or snow or even wet grass and on wet roads it hydroplanes in the rear so you have to drive slower and always worry. I agree I have not seen the difference in fuel mileage difference, but the difference in how it handles is very evident and I think all 4x4 trucks and suvs should be full time transfer case for safety. Thank you and loved the video. Its only my opinion for what that is worth.
As an Automotive engineer in the industry, part time does save on fuel. Not in the litres/per hundred however, more so in the 0.1 litres per hundred. You have to understand with new Euro emissions, saving 0.2 litres per hundred is massive.
100 series V8 literally saves over 1L/100km. Since the conversion, I get 40-60km extra per tank.
You don't seem to understand WHY people want part time 4wd, you're focussed on your overlanding perspective. Your mechanic tried to tell you in your last video that they're fantastic in a "make a plan" emergency situation, but you were too angry at your failure to identify obvious mechanical faults with the vehicle you bought and instead focussed your anger on the modifications.
Reliability factor 1, damaged CV/Birfield joint:
With part time 4wd, if you break a CV/birf on the track you can drive back to camp in 2wd with the freewheel hub disengaged as if nothing happened, and safely make any repairs in a chosen location. No track side repair, no driving along crunching and ruining hub internals requiring a full rebuild of all components, greatly reduced risk that the damaged birfield will seize and jam steering. With full time 4wd you're f^&*ed on the side of the track and forced to repair it in a potentially dangerous location, or you drive on damaged components with serious danger of losing steering.
Reliability factor 2, damaged diff:
Damage a front diff in permanent 4wd, congratulations - you're f&*(ed. You can disconnect the drive shaft... but because you hate freewheel hubs for no reason you're screwed. Damage a front diff with part time 4wd... no problem at all, just unlock and RWD home!
Reliability factor 3, inner axle seals:
Part time 4wd, inner axle seals have less diff oil bypass, and less wear on the front axle. Grease getting into the diff is not the issue (in fact it's completely false). The issue is diff oil getting into the hubs and washing grease from the bearing and birfields. Vehicles with low maintenance have low diff oil level resulting in heat etc, and often have water in the diff oil which ruins the facing through foaming, lack of lubricity, and cavitation in the fluid film between gear faces. Notably, axles/birfields are not cheap to replace (NB: yours were ruined where the inner axle seal had worn a ring into them as they're always spinning in full time 4wd... thats an expensive repair)
Handling factor:
Put part time 4wd vehicle in gear as soon as you hit gravel road... congratulations, handling and braking has improved! Hubs can be left locked in with no ill effect, so the argument of "but you have to get out of the vehicle..." is childish and moot.
Reasons manufacturers rarely fit freewheel hubs on modern vehicles:
- On road performance is more important to sales than offroad reliability
- Aisin hubs are $300-$400 retail! Bean counters love drive flanges.
- Generally, old people buy new 4wd's, and they don't want to get out to lock/unlock hubs. They even prefer notoriously problematic and unreliable push button electronic/pneumatic 4wd engagement. Modern 4wd's are luxury barges and not rugged purpose built machines.
- Front diff centres aren't the same as rear diff centres anymore... because of cost cutting bean counters! The benefit of being able to swap centres on the track is gone, which is an added benefit of having freewheel hubs and part time 4wd to disconnect the front diff.
not sure why you would ever want full time transfer case unless it had a 2wd option like the np242
You raise some very good points and I agree. The only thing with a part time 4wd is when disengaged, both ends (transfer and front wheels), on rough roads the front diff pinion bearings get a hammering so after a while the diff will "growl" because the bearing has roller indentations, own two 62's, both have the problem, doesn't stop the vehicle but not cheap to fix unless one has the tools and knowledge(I dont). Something to think about with a part time 4wd I guess.
Go to any 4wd training, they'll teach you that the vehicle handles and stops better in 4wd and you should engage it more often than you think - no harm in driving in 4wd whenever you're off the tarmac.
If you don't know how to repair stuff, you're screwed with full time 4wd if you break a diff, birfield etc. Renders the vehicle undriveable!
@@paulboon1100 most manufacturers will recommend you "use 4wd for X miles every X miles" so that doesn't happen.
@@Tanner731 , full time 4wd is great for what we call the Toorak tractors - better on road handling in the wet etc.
Worse for bush repairs, better for city slickers.
Every time I hit dirt rd I just pop it into 4 wheel automatically. It always feels like the passenger disagrees. Thinking...already? You've put it in 4 wheel? We dont need it. I eventually explain what you just ranted about. Love the work Andrew. Keep it up!
Dirt roads are what 4wd high is for, it says so in your manual & earlier Toyotas had it on a sticker either inside or outside the glovebox lid.
That's the beauty of full time awd with locking center diff. I can hit the dirt road and be fine in awd. Things get tough I just lock the diff.
Exactly, put the part time 4wd in 4H as soon as you're off the tarmac and all his rants about handling differences become moot...
@@scod3908 well if it's wet, 4H (AWD with open center diff) is an advantage even on tarmac, isn't it?
I'd rather drive carefully in the rain like every other RWD vehicle on the road and know that I can get out of trouble when I'm in a remote area which is what a 4wd is supposed to be for.
It's nice to see a video from someone who is NOT at SEMA.
When recovering a vehicle, the part time system allows you to use different combinations. Sometimes we do not want traction on the front wheels or sometimes we just want to place the reduction gear without activating the front transmission, for example in areas with very tight turns. Part time its most versatile.
Can you give any example of one such particular scenerios where you don't wanna send power to to the front wheels?
It would not make a difference
@@GRcorolla-bt3mn when I’m off-road and I break a front axle, then I get put it into 2wd and drive it home. Also, will save a small portion of fuel by only driving 2 wheels. Also, the vehicle becomes easier to steer when the front axle is not being torqued. This muppet has no clue.
@@EnkeiTenjin hmmm makes sense
Sometimes we do want all traction of tire but not 1:1 traction!. AWD is also needed
Also don't forget you get better fuel economy by going north to south in the southern hemisphere. Why? You're going downhill............
Yeah, but more tyre wear on the left because of the Coriolis effect!
When I was a yougin I thought the globe was just convenience, because its obviously not a globe, only if you look at the TV or go to school it is a globe, in the real world, it's flat, and we need to go back to the drawing board when talking about part time 4x4 conversions, wear, and consumption. 😆😂🤣
The earth's constantly spinning sometimes we on top sometimes we on bottom
@@ElisPalace that's what everyone says but to me it looks still, and it's all the lights up in the dark are moving or what's called the sun in daytime.
Not true! The earth is flat
MY company every 3 years would replace MY f 250 4x4 or f 350 4x4 part time. I would alway lock the front hubs for the first 2,000 miles to ware in the grears and bearings. Then run unlocked on pavement, then lock them when running for miles off pavement. I noticed on measurable differences in fuel milage.
We grew up with the same trucks and also saw a pretty significant fuel savings when in free spool as well with the f-series trucks. plus, it meant that the kid who got the window seat also had to jump out in the snow and flip the hubs where the kid that got stuck riding in the middle (who we get whacked in the knee every time his old man shifted into 2nd and 4th gear) at least had dry boots when we got to school! ;)
Can't drift around a wet roundabout with constant 4wd though ☹️
4 wheel drift?
Yes you can!
You just don't have the power then
@@FlatlanderGear what 4x4 these days come with free wheeling hubs besides 70series
Sure you can, you just need more power.
As I understand it Part time 4wd like the old jeeps combined with manual locking and unlocking wheel hubs will save on wear and tear on the front axles and diff internals as they wont be spinning. So when it's disconnected in 2H the entire setup isn't spinning and therefore an argument could be held on that point. However it is important every now and again to engage these parts to ensure they are getting lubrication and that bearings aren't consistently riding on a static position.
it also stops the classic landcruiser driveline cluck
Actually, this argument is logically invalid.
The difference in wear & tear savings over a span of 100K miles is negligible. But more importantly, why do you think saving a few negligible miles of wear and tear in the front drivetrain is more important than the REAR drivetrain???? The rear is spinning all its life, so if it can survive that then surely the front can handle it too.
@@hanrahi9030 I’d much rather just run on the rear diff and repair rear diff than all the extra work in constant maintenance in swivel hubs and CV joints - ever done that work yourself?
@@ZuluGoatHerder - Well, you are arguing for 2wd on a 4wd page.
Whether I do the repairs myself or pay someone to do it is besides the point. A rear diff typically doesn't break down even after 200k miles. If my front diff lasts for 180k miles, that is still a good deal.
I have a Triton with super select and have never liked 2H, I tried driving a couple of days in the 2H mode and vehicle did not feel as stable on the the road. Fuel wise I would rather have a more stable vehicle than save on 1lt per 100km.
This guy talks from vast experience and not trying to sell you anything, a refreshing change.
Well said Andrew!! I’ve been driving all sorts of 4WD’s since 1978 and l drive them just as you do. I leave the “free wheeling hubs” in the locked position and when l leave the “dry” bitumen, l select 4Hi or 4Lo as required. Safety is “paramount” to me, at all times. Keep up the good work mate...you’re the man.😊👍🇦🇺🦘
I had a 2002 Toyota 4Runner with what Toyota called multimode 4wd which allowed you to drive in 2wd, AWD or part time 4x4. I drove it a month in AWD and noticed 0 difference in fuel economy. Driving improved greatly on twisty roads and acceleration from a dead stop when turning onto other roads was obviously improved. Because of fulltime awd there was far far less intrusion from the Vehicle Stability Control which was notorious for cutting engine power in 2wd because of a little bit of wheel spin. I wish I had that system in my FJ Cruiser because I found it extremely useful.
What about if you break something in your front axle? A massive advantage of a part-time kit is the fact that you can unlock your hubs and stop the front internals from spinning and causing further damage while you limp your way home.
That is a $500.00 luxury that you probably will never use.
I’ve wished I had it twice. Would’ve saved me thousands
What if you break something in your rear axle, or gearbox, or have a heart attack, or if your wife dumps you?
That's a good point however you can generally still disengage the front. Take the drive shaft out and depending on setup the CV shafts can come out. Now on a solid axle vehicle that's another story but most modern vehicles don't have a solid axle. If you need to you can generally limp something off a trail to a tow truck
Most SUVs hardly need the use of 4wd in real life. For example, my pajero goes off road about 10 days a year. In this regard, my experience is that the part time 4wd (2H) makes the front parts of the drivetrain (ujoints, front diff, CV joints, CV boots ect) wear less. In my pajero, haven’t touched them since I got it 10 years ago. Another experience I have is, in a Hilux (2002) with IFS, the CV boot was torn and the vehicle has run in part time 4wd with manual locks open for a very long time. But this has not damaged the CV joint as it was not rotating. A bit of cleaning and a new CV boot did the job.
I could be wrong but don’t you think 2H make sense for vehicles that hardly go off road?
Be careful there afaik the pajero uses a disconnecting front diff which means all the front stuff is spinning all the time
Hi. I have a Pajero also with Superselect system ie 2H, 4H, 4H Lc, 4L Lc. (Lc=Locked centre diff).
Using 2H the front driveshaft is not powered but will be driven by the front wheels rotating UNLESS you have either Auto Locking Hubs or unlocked freewheeling hubs. In this mode you may see a slight improvement in fuel consumption.
The trap in this mode is that stupid owners leave it in 2H forever and the parts will deteriorate unless turning. Rust in diff, seals sticking, CV joints drying etc. Use 4H now and again to avoid this. My preference is 4H 100% until offroad when 4H Lc/4L Lc is the go. I feel the car handles better in AWD (4H). Cheers
And the other benefit of running with the front drive parts engaged is that they stay properly lubricated - the CV/U-joints at the steering knuckles, the front propshaft joints, and ring & pinion bearings, etc.
I've heard arguments about this causing "premature wear" on the above-listed parts, but they aren't going to wear any faster than the rear parts.
That said, a common problem with Land Rover Discovery IIs is that the low-range lever seizes up. This is because it's so rarely used. The same goes for the entire front drive train. If you want it to work when you need it, it needs to be exercised. A system that doesn't get used until it's needed is far more likely to fail under pressure than one that is always in use.
Andrew, I'm with you.
/rant off
Lies my bmw x drive has been rwd for 5 years no problem
@@MrApple187 yep. and your front CV boots are probably dry-rotted. They'll fail soon after using them again and if you don't catch it, the CV joints themselves follow shortly after.
And what happened that you've never needed four wheel drive in five years? Dude, get out on the tracks and have some fun!
@@slateslavens I need a little lift first going to be doing x5 front end swap but I guess not the whole 5 year I use the awd once in a while like just a couple months ago I got it stuck in sand and was struggling to push it lol till I remembered and I plugged my transfer case actuator lol and hot it out but i use it once in a while but on the street it runs rwd
@@MrApple187 cool! Shoot some video while you're doing the swap and post it up!
I did the part time conversion on my 2000 LC v8. It really helped the car feel better on dry pavement. I only have 33’s and it handles so much better. Tighter turning circle, transmission seemed to shift smoother, steering feels a littler lighter.
The down side is I do have to pull over half way up the canyon to lock the hubs if it’s snowing bad. The other is with open diffs and no limited slip, in it’s basically 1 wheel drive on ice in 2x4. Another upside is it should wear out my ifs cvs a lot slower.
Old man yells at clouds
OMG that's so original!
I've driven a Land Rover with just Rear Wheel Drive. It just doesn't feel right. They drive so much better with full time four wheel drive.
That was a fantastic video and made clear one of the things I rant on about to other people about my 1994 80 series Toyota . It’s not worth the money for the conversation and you get nothing in return except a less capable vehicle.
I did the part time conversion on my 80. The steering is lighter, and there's less backlash due to less parts spinning. Plus touring in Australia means 1000's of ks on bone dry bitumen where you don't need AWD at all. Overall though I could take it or leave it. If I had to do it again I'd probably leave it alone.
I get the opposite. My ute has backlash in 2WD and has none at all in 4WD. It all depends on where the backlash is coming from.
May i ask something? (i am not that familiar with such conversions) When you say "part time conversion" does this mean it then works basically like the 4wd system of a Jeep Wrangler? ->you eliminate the center diff, and put a form of coupling in that you can close to swithc to 4wd? So that there is a strict connection between the two axles. (like a locked center diff) but when you open it, no power goes to the front wheels?. Because if that is the case, the same parts are turning if you switch to 2wd. They just don't get direct power by the engine, they get turned by moving the car. (so you get loss from the power having to go through the wheels over the gound to the front wheels.
@@nirfz It's been many years since I had a Jeep, but they used to have Command Trac (4WD) and Select Trac (AWD, IIRC). One was 4WD and one was AWD. Your basic 4X4 has 4WD but it only works well on loose surfaces since there is no centre differential - only a transfer case. If you drive one of these basic "part time" systems on tar, you get windup (axles storing energy from travelling at different speeds) and tyre scrub as the energy is released on turns, etc. Accelerated wear and weird tight steering result.
On AWD or "full time" 4WD systems like LR Defenders, there is a centre diff that is normally "open" so the F&R axles can travel at different speeds but still get drive (also you have the regular axle diffs that allow L&R wheels to differ so you can go around corners). This can result in more settled handling and less tyre wear. But you could still get stuck with only one wheel losing traction as all the other diffs are open. Hence the need to lock the centre diff (and on LC's you can lock the axle diffs as well). A locked centre diff means you have to lose traction on both axles (at least one wheel) to be stuck and locked axle diffs mean any one wheel can deliver power (whether that's enough to unstick you is another matter).
And then you have the traction control computers (selective wheel braking) and so on. As fas as fuel consumption, none of this matters much (as ASPW discusses above) when you look at the mass of these vehicles, their load and especially the effects of wind
Impossible mate. The internet experts disagree!
@@stevep8773 I am familiar with the theory of how that works, i wrote that i am not familiar with the conversions.
So i wanted to know what his conversion inlcuded.
As for the Jeeps, as far as i know the Wrangler never got an awd system with center diff. It to this day has a part time 4wd without center diff. That's why i chose it for the comparisson.
every 4x4 i have owned except for my old power wagon have had part time 4x4 and can say that the steering gets heaver in 4x4 on most of them. add locking front diffs and the locking hubs make a huge difference on road
I have an F250 4x4 and a Lexus LX450 all wheel drive with triple lock differentials. My F250 is a beast and I have NO complaints. I understand its engineering and its limitations. The 80 series is an extreme rock crawling reptile when it is locked. Both of these monsters are fuel hogs. I have a 4Runner 4X4 and another 4Runner 2x4. They all have their limitations depending on what you are demanding from them.
While I agree that one would probably never recoup the cost of a full-time to pert-time conversion through savings in fuel consumption, it is a well-established fact that disconnecting the front axle by means of free wheeling hubs or any other means WILL improve fuel consumption. Case in point: Jeep's new Wrangler JL (2018) is fitted with a front axle disconnect system (FAD) for that very purpose (squeezing out a few more mpg).
YES. 2WD WILL improve fuel consumption, and only on dry tarmac and by 0.001%. A minuscule saving for the cost of safety and increased tire wear. Driving 2WD is a net loss!
It's physics more drag = more power needed = more fuel . I don't care what story you tell Physics don't change because you disagree with them .
@@jimbotheassclown He's suggesting, quite rightly, that the amount of power needed to overcome that drag is so minuscule as to make no difference. You can rotate these components in their housing by hand, a 4.2l diesel will not even notice the tiny increase in demand.
@@4xoverland correct me if im wrong andrew but is the net tire ware not more with awd? Less tire ware front more in the back with 2wd? My point is less overall tire ware in 2wd?
@@4xoverland Respectfully, your findings expressed w.r.t your Zambian friend's Pajero is anecdotal and does not take into account that the vehicle was not fitted with free wheeling hubs - the front driveshaft, differential and side shafts therefore, were still spinning in unison with the associated drag/friction/power sapping rotational mass; resulting in the minuscule saving in fuel consumption you describe. I'd like to suggest a collaboration with Bill the engineer (Defender Mods & Travels) who will happily (I think!) crunch the numbers and provide the data to settle this matter once and for all. If you're watching, Bill - how about it?
After replacing the chain in a full time transfer case 3 times. I made my transfer case a part time one with a kit. And never had to replace a chain again
Chain?
Woke up this morning and saw the notification of this video and watched it. It's refreshing.
Thank you Andrew for being the way you are!
Besides the fact that you are completely right on this.
Thanks Andrew! This is encouraging! As the owner of a full-time 4WD 100 series land cruiser (US spec) I think I will spend my money on other modifications instead of a 4WD to 2WD conversion.
WW2 Jeeps has a disconcerting habit when in 2wd , of not always going around corners and turning the steering wheel suddenly at speed could make the vehicle turn over .The US Army got an engineer named Warn to find out why and fix the problem , he discovered inertia of the extra rotating mass of the drive shaft , axles etc , in some circumstances, caused the Jeep to become reluctant to respond to steering wheel inputs and want to go straight ahead . He came up with free wheel hubs , which were turned in or out by a spanner , after WW2 he left the Army , he came up with hubs that could put in or out by turning a leaver on the hub . I have an Aussie mate who had a Land cruiser 100 series , he had the full time 4wd changed to selectable 2-4 , he said in black cotton soil areas of Australia at some times of the year it was illegal to use 4wd on the dirt roads , True or not ?
No man landcruisers are full time 4wd the only thing center lock does is give a 50/50 split normally it’s 60/40 rear to front. The reason people change to part time is so the front diff and axle aren’t spinning all the time wearing things out sooner than a part time system. On my 1986 surf with part time and free wheel hubs my CV’s lasted 34 years before needing replacing ... on 90’s surf with auto locking hubs the cv axles wear out way faster because they are constantly spinning even when you aren’t in 4wd. Your diff and axles will work more and wear out sooner with full time. You are probably right about the fuel consumption argument but I don’t agree with the rest.
As others have said; the point of fitting part time 4x4 is that it gives you the ability to isolate the front drive train if it gets damaged on the trail. Unlock hubs and transfer in 2wd makes the front prop, diff and CV's stop spinnig when driving. That way you can limp home and repair. Broken CV or front diff on permanent 4xd means you are up shit creek and have to repair in situ or drive on damaged components risking further damage and/or steering lock up from your CV's exploding. Removing the front propshaft and locking the center diff does not help, CV's and diff are stil spinning on a car without free wheel hubs.
Exactly! This is what Andrew and the majority of those commenting here do not understand. Plus, the rotating mass of differential gears and side shafts rob power, and will cost you in fuel consumption.
I love the feel of AWD (vintage Audi guy) BUT in my Jeep - I broke a rear driveshaft and was able to lock my front hubs, disengage my RWD (twin stick transfer case) and got home driving the only front wheel drive 454ci Jeep :)
Series 3 Land rover, half shaft snapped in traffic, popped into 4WD and away on black top, No free wheeling hubs so did it from my seat. Cheers
You can do this in a permanent 4wd as well, by locking the center diff, and removing either the front or rear propshaft
@@Taun1000 Removing the front propshaft and locking the center diff does not help, CV's and diff are stil spinning, driven by the wheels, on a car without free wheel hubs.
I agree 100% ! My 2010 6 speed manual TRD Off Road Tacoma is a great truck! That being said, I wish it had the fulltime transfer case from the 2007 6 speed manual Fj Cruiser I traded in for the Tacoma. For an off road oriented SUV it handled like it was on rails and would out run the Tacoma and many other vehicles on any surface especially the moment it was wet, muddy or covered with snow.
Thank you for giving your experience and observations! You couldn't be more correct. I drive daily on snow, ice, sand, and asphalt (tarmac) and wonder every day why my truck has a part time system. I constantly have to switch from 4wd to 2wd because of changing road conditions. I wish I had a full time conversion. Keep up the good work! Cheers from the USA!
Hi Friend we have find that there are less vibration and more confort in highways with the hubs in Free Position. for slippery roads and high velocity in off road is much more secure to use Lock position and H4 and the vehicle handles so better you can feel the grip and performance in each curve. Thanks for the video so interesting. for Highways in summer we recommend Free Position Hubs and H2 the vehicle handles so better
Until the argument looses traction it's going nowhere...
😁
I get it
I see what you did there.
Gripping stuff
just wait till it loses a CV shaft
You’re just winding him up 😃
Hi, I want to start off and say that this just video just saved me a lot of money by convincing me to not do the conversion.
THANK YOU!!!!
I also wanted to share that a mid 80's Chev Blazer with the hubs locked but the transfer case in 2wd will use about 3 more mpg then when they are unlocked and you can feel the wheels fighting the steering wheel while going around corners.
was thinking to do the same on my fulltime 4WD, all time 4H 2005 Fortuner for improving FC.
now im leaving it as it is. superior road grip noticable at rainy tarmac.
Totally agree Andrew. Are we getting a Christmas countdown this year?
This is one of the few times that I agree 100% with Andrew! Most of the comments for converting to part time are so easily counted with fact not just opinion
I have the rare full time 4WD with 4 Lo option on my 2005 Chevy Tahoe. It is amazing in the snow. It’s the Borg Warner 4482 transfer case. It has full time 4WD (60:40 split) and the 4 Lo button that allows the center diff to lock it to 50:50 torque split. But it has no 2WD option. Sometimes I wish I had the standard transfer case. But, it’s a very unique setup for sure. It’s a similar transfer case to the Borg Warner in the Hummers (BW4484) but mine lacks the 4 Hi (locked center diff) option and the Super Low option some Hummers have (3 speed transfer case).
That’s why I love my 2017 triton. Best of all worlds. Can drive in 2wd you can have it drive like an AWD - then you can lock the centre diff for 4WD with hi and low range.
When in 2wd does the front diff spin always, driven by the front wheels? That's what I dont want.
same system as the pajero and alot of other late model ifs vehicles, theres a vacuum solenoid on the diff to actuate unlockable hubs inside the housing. yes the axles them selves still turn yes but not the diff. its also a good way of keeping the cv boots soft.
Interestingly, I've done this very same test, in 4 different 4wd trucks I've owned. My second ever 4wd was a 1996 Jeep Cherokee 4.0L country. It had a multi select transfer case like Mitsubishi has where you can go 2wd, open diff 4wd, locked diff 4wd HI, neutral, Locked 4wd Low. I drove that thing for almost a year on normal roads in 2wd before one day thinking "Hmm.. I should try out the full time 4wd" (this truck had a limited slip center diff, so it was a good 50/50 system) I had been measuring my average fuel consumption over the prior year at roughly 15.5mpg (I still have the records on it and every truck I've owned) So I tried full time 4wd. There was basically no difference. Roughly 15.5mpg is what that truck was destined to get no matter what the lever was set at over the course of a month. So I left it! Why not? It's was more sure footed in crappy conditions, and locking the center diff just required one click up on the lever vs 2. Later on, I'd have a 1981 Toyota HiLux (22R, 5 speed transmission, part time 4wd with lockout hubs) As soon as I bought the truck, I decided to test it to see if the hubs being locked vs unlocked made a difference, and it made zero. The only thing on that truck, was if in 2wd, you could feel extra vibration while driving with the hubs locked, which I attributed to something being perhaps worn out, but I was never able to track it down. Further down the road, I had 2 different Chevrolet Suburbans, one from 1989, the other from 1991 (2nd was a 3/4 ton, so solid front axle, lockable hubs) Both trucks, tested and found the hubs being locked made absolutely no difference in fuel mileage at all. That 91 suburban was my final part time 4wd vehicle after that, as I find the full time 4wd is just a safer all around option in wet weather/snowy weather. My 1996 Land Cruiser 80 was effortless in all weather, and my current 2008 Land Rover Discovery 3 is perhaps even more so, because of clever electrics (which I know you kind of loathe, but I've conquered that fear via programming) Great video, and great discussion!
Have you considered that your '96 XJ, whether in 2wd, 4wd part time or 4wd full time, the front drive shaft, differential and side shafts still spin together, and for that reason you will not notice a difference in fuel consumption? Fitting free wheeling hubs and select 2wd will get you up to the high teens.
Will Actually I have considered. But I’ve also had vehicles with freewheeling hubs and it’s made zero difference.
As long as low range is there i can make either system work
Totally agree Andrew!! 100%
Only because you're incapable of independent thought.
@@willactually7509 true
Excellent video and you’ve said what I’ve always suspected.
It depends on the surface. On dry tarmac 4WD is sufficient, off tarmac AWD is always more even and ready for action. I see the problem rather in the fact that the Land Cruiser cannot engage reduction/low speed without closing the inter-axle differential. For example, on a rocky surface it's a pitty, the wheels should roll more freely. For example, the Pajero/Shogun 4th generation has a clever drive solution. You can choose like you need, it's not just classic 4WD-AWD.
You are absolutely right until... you break a front cv or a front diff in a permenant 4wd and usually in the worst possible places.. I know that buying a 70 series part time 4wd is the best solution but until then I will keep enjoying the rock steps and mud slides in a permanent 100 series converted 4wd and a spare greased cv ready 👍🏼
How often have you broken a front diff ? It's pretty rare.
It depends on how often i go rock crawling.. which is quite often for me and when it breaks, that pointless conversion is the thing that would always bring me back home and let me drive to work the next day no problem.
I wish my part time 4x4 Hilux was permanent 4x4 especially in the winter when the roads get a bit sketchy.
good to hear this, I leave my delica in 4x4 all the time because of safety and tires. I decided that the 'extra' fuel was worth it, but if its not using more fuel, then its definitely worth it!
I did the conversion on a 1hdt 80 series.. definitly used less fuel, had much tighter driveline (less clunking) much lighter on the steering... that said it was frightening to drive on wet roads and would spin the back wheels all the time. I would not do it again but in my first hand experience some of your points are just wrong.
Andrew, I'm not the kind a guy who comments often on videos in general. this time though I completely agree with your "little rant". Thanks for being so honest and passionate in your videos.
I was about to buy a full time 4wd Land Rover defender, but after watching this video I am researching to buy a part time 4wd Land Rover series 3.. Thanks Andrew!
Agree with all points from Andrew, apart from one, wear on front axle, my 1994 patrol has no wear on the front half shaft, my 1996 80 series has a considerable groove on the half shaft as its permanently spinning, now that's expensive to replace!
$50 speedy sleeves or $100 for new shafts. Done both options on my 2 80s. Bearing wholesalers for those prices.
Michael Bansagi or when putting in the new inner axle oil seal into the housing just don’t tap it in so far say 2-3mm out and then it’ll wear on the new surface not the grove. Good for another 500,000kms. The 80’s however seemed to wear more on the brass spindle which they fixed in the 105 to small roller bearings.
Completely agree. I have been wanting a pickup, but none of them come in AWD in the US that i'm aware of
I have to agree with you. I drive a 2004 Toyota Sequoia Limited with the 4.7 v8 here in the USA.
I can drive it in 2wd or 4wd high (center diff unlocked) and i get .2 mpg more in 2wd . With it in 4wd High it feels more planted and stable on the road.
I had a 1916 Subaru Forester All Wheel Drive and loved it. I could be quite sassy with it. One time I did get stuck when the whole vehicle fell through ice on top of snow and bottomed out on the frame, leaving all the wheels spinning. I think the weakness of my vehicle is that it had a whole plethora of electronic, fiddly bits, and if they malfunctioned... Still it was quite a lovely car.
Completely agree with you Andrew. Just got your Four-Wheel drive book. Guess I get to reading this beautiful Friday afternoon. Cheers from Las Vegas!
Andrew, I agree 1000% with you. We also owned quite a few 4x4’s, what I cannot understand is why someone will do that, and not fixing it when back at a proper workshop….
Was the best mod I ever did. Didnt do it to save fuel, did it for the comfort of my 105, removed 99% of torque steer, no gearing backlash smooth gear changes. You say no positivity in fuel consumption i say wrong, 0.3l/100km better is still a positive difference. My on road pick up 0-100km is also better. I didnt do free wheeling hubs or any of that just the transfer case spindle and honestly i have never been happier best thing i have ever done.
A little late but I wanted to say why I have considered it: I have a beat up 100 series, ifs. Any slop in the mounts of the front diff is felt on slowing and downshifting, pulling the rig slightly off line. Next the 100 supposedly has a weak front diff, some have broken from a quick slip reversing out of a parking space to sold traction. So the 2wd conversion eliminates that possibility. And as mentioned, those of us who like to go sideways around corners like the rear wheel drive.
Now to counter my own thought process here: I've gotten used to the shifting of the rig during downshifting and slowing. The weak diff? I don't know. Just going to find out for myself. And the money I would spend on a conversion (even welding the center diff myself) would cost more than new diff bushes.
And finally my first drive in the 100 was over the cascades here in oregon with strong winds and heavy rain. I felt very confident and comfortable even in the standing water on the roadways.
So I won't be doing it.
This is why traction systems like Jeep Selec-Trac or Mitsubishi Super-Select are some of the best systems in the world, because you have all the options to choose (2WD - 4WD Part time - 4WD Full time - Neutral - 4WD Low Range).
I have a Jeep KJ with factory Command-Trac system (Part time) and I always missed being able to use 4WD in wet pavement or even in some off road situations like, when turning sharp where you can feel your trans binding even in the dirt.
A couple of years ago I made the convertion to a NV242 Selec-Trac systems (basically changing the transfer case, the lever and reprogramming the body control module) and it's one of the best mods I have made to my car.
Incredibly this is a rare modification because people usually tend to think that Jeep NV242 transfer cases are weaker than NV231 ones. It is totally false. Humvees came from factory with NV242 and Jeep now offer it as an option in the Wrangler. Something never seen before.
There is a reason. For guys running chromoly axle shafts, reduced wear when driving on pavement. Also the center diff is a potential failure point.
fwiw i agree. i had a late model pajero and coud never discern any difference in fuel economy between all wheel drive and 2 wd drive.2wd was dangerous at intersections.In 2wd it is quite esy to spin a rear wheel and the traction control on my 2009 pajero was very intrusive.For that reason i ussually drove in all wheel drive.
the only benefit I can think of for a part time kit is reduced wear on the front driveline components when the front drive is not engaged. both a stock fulltime and a stock part time vehicle are essentially only going to give drive to one wheel until you lock the centre either by engaging the centre diff lock or going into 4wd. because of this the delivery of the drive isn't really much different
A lot of people convert our Hummer H1's into selectable 2wd. Many of those people have removed those transfer cases subsequently.
Fully agree, that is why I love your channel, always the TRUTH based on facts and experience, analytical and clinical. An opinion you can trust.
I have a Jeep Grand Cherokee here in the states and it has 2 high, 4 high and 4 full-time and I always keep my transfer case in 4 full-time because I get better handling, and on accelerating, the rear wheels have a tendency to break traction especially when accelerating from a stop and making a turn. When in 4 full time, the Jeep just goes. I totally agree with you!
only gain you can possibly get is an AVM front diff disengage, with which you literally separate mechanically the front wheels from the front differential, so they spin as if in a rear wheel drive car. This way the front diff gets completely disengaged and is not "forced to spin" generating drag. any other situation, full time AWD is better.
Totally agree Andrew. The engineers at Toyota don’t often make mistakes, except for the narrower rear diffs in some models.
I believe in leaving vehicles as stock as possible for reliability. If it’s not broken, don’t fix it.
Hi Andrew
I have a 94 jeep ZJ witch was a all wheel drive, but it did't t have a locking central dif . So i i changed the trasfer case and now i can locked it. You are right abought the gas millaege - only 25 - 30 miles per tank. But now i can lock my trasfer case in low and hi gear. Witch was worthed for me. Thank You for You videos
I have a 1979 Dodge W150 Power Wagon, and it has the NP203 transfer case(4x4 only, High Low, High Lock, Low Lock), and I've seen guys on forums talk about converting to a NP205 or doing a 203 part time conversion, and quoting fuel savings as the main reason for doing so. I don't understand that concept because most of these trucks have either a 5.2L or 5.9L(in my truck), so fuel economy is trash to begin with. Seeing as how my truck also has a 4 barrel carb(800cfm Thermoquad from the factory) and a 4 speed manual (NP435, 6.68 first, no overdrive), fuel economy should never be a consideration for mods, unless you're looking to add overdrive.
They are a great idea on the HDJ100 as it saves the CV's
But like anything, there are Pro and Cons...
The only Pro is when you are on the Black top
Its shit to have the front disengaged off road or on gravel roads.
If anything, it may negate understeering on a bitumen road when really pushing it
For a 105, i cant really see the point, 100 yes for saving the CV's
The downside is you can get a heavy vehicle that will oversteer on wet corners with high throttle applications... Sometimes when unwanted.
I am glad you posted this video. I own a 1991 fj80 and was thinking about this mod but was on the fence about it. now I am going to save money for something else. thanks!
There are other good reasons to do the mod apart from fuel consumption
Thank you Andrew. Was considering this for my ‘97 80. Appreciate the content and Happy New Year!
Agreed completely. The internet is inundated with people providing false information, especially those that own capable 4wd vehicles but rarely, if ever, venture off-road.
Muchas gracias, Andrew! My 79 jeep wagoneer shall remain full time quadra trac, a decision I already made but which you have nicely backed up.
I have been driving off road and in all sorts of weather conditions on 4 continents for 50+ years and I agree 100% with Andrew's points of view and explainations!
Well said. I have a 1975 chevy suburban with np203 transfer case and would never consider a part time conversion
I recently had the front prop shaft out of my 2003 Grand Cherokee which is full time 4wd, I did notice a tighter turning diameter(handling?).
I have a WJ Grand Cherokee. 4all is a misnomer. The Quadra Drive system is rear wheel drive unless one of those rear wheels starts slipping. At that point the gerotor in the centre diverts power to the front axle in a progressive manner. It is only proper 4wd when in 4low and the centre transmission is locked.
I respect your passion and vast 4x4 skills and knowledge. And i respect the idea we can disagree and keep our blood pressure down :) it is personal preference now. Back with a carb and locking hubs and t case with 2 high and 4 low the parasitic drag was real thing. Unit bearings and efi have no doubt made the argument less viable. So mmm e 4x4 grand cherokees come with full time 4x4 with high and low range. The vast majority here in the US prefer a t case with 2 hi 4 hi. N and 4 low. In my own jeep cherokee in 4x4 hi range lots of binding and drag in the drivetrain when turning. Mine is a 1988. Leaving in 4x4 hi range in everyday driving kills my fuel economy. Fyi i also have f and r open differentials but larger tires. My unit bearings are nearing 275,000 miles. Still tight. No howling no bleeding rust either.
Brilliant. I am going to go with full time 4WD Toyota hiace now, whereas before I was concerned not to have 2wd option. Thank you!
Probably the myth began with a subaru AWD cars. Those cars consuming more fuel then the front weel drive cars like toyota's. But i think the problem in that case is the boxer engine design is less eficient then in line four cars. I like your chanel very much. Salute from Chile.
Interesting idea although as a Subaru guy I could tell you that pulling out the 10A fuse on older Subarus (called the towing fuse) which effectively turned the vehicle into a front-wheel drive - gave me a 4 to 5 mile per gallon improvement in fuel consumption and a significant improvement in off the line pick up. I modified my fuse box so I could flip a switch on my dash switch trigger relay and completed the circuit so I had front wheel drive and full-time all-wheel drive when I needed it. Best part about that car was that the mod didn't require any real changes to the vehicle! I did have some tire wear issues however - but that was just because of all the front-wheel-drive burnouts I was doing - hey, I was young!!!
All time four-wheel-drive is an awesome system. Land rovers and land cruisers that have the locks on each axle are ridiculously capable
Yup - '93 3xl 80.
Land Rover do not make use of front diff-locks, only rear. And only from the Disco3 onward (incl Range Rovers) AND Land Rover is daft enough to make it a factory optional extra! And Toyota were stupid enough to deprive the LC200 from any axle-locks - only traction control...
Just couple days ago change part-time tc to full-time with VCD on my 80 series, and now I'm absolutely happy.
Interesting Subject , I have a 91 VX 80 Ltd ,owned it for 10 years . It was a Triple Locker + Factory Winch nice truck . My friend whom I purchased it from got it stock & did an 80mm lift & Part Time 4wd kit & free wheel hubs . It handles bad at speed on motorway etc . My feeling was no Adjustable Panhards miss aligned diffs was the main problem , but seeing your discussion on AWD better handling it's made me think again about the problems . I have just bought another 90 VX Triple Locker & Factory Winch all original so will be interesting to compare .
The one thing that affects fuel consumption more than anything else is the nut that holds the steering wheel 🤔👍🏻🇬🇧
Part-time kits are cheaper than replacement center diff and makes an old drive train smoother on road + skids and doughies are fun
Hiu Andrew
My 2 cents worth is not about fuel consumption or wear and tear but about towing and in particular maneuvering a boat. I use a 4wd vehicle as I often launch and retrieve from sandy, muddy or rocky unformed locations (not a boat ramp). But moving from a vehicle with FWH's to locked hubs I find that I miss having the ability to use 2WD low range. Particularly when maneuvering (backing) into tight spots at home (concrete and bitumen). I also appreciated low range on difficult boat ramps, not needing FWD but the ability to crawl into position. Maybe its a symptom of my clutch control but I found that I didn't need to ride the clutch to obtain the slow speeds sometime necessary. Just a different perspective on the argument.
Maybe I missed it?, but I didn't hear a test with the front hubs unlocked and the lever in 2wd. Without all the front components spinning for no reason it would seem you could save on fuel?
Logically, one can save fuel and it probably does save fuel. But it is so little, that any mod to do it is pointless because the fuel savings are so small, and the cost to safety, tire wear and handling is so high that the result is a net loss. It's a myth promoted by companies selling the kits.
Thanks Andrew for all you great content , I just love your shows .
I drove the dirt high highways of the flinders ranges last year and 4wd definitely improved my handling in my 2008 triton ,around bends ,wild life ect. I did notice minor extra fuel consumption. but I must say that the improved safety factor that comes from the improved handling due to 4wd on loose surfaces far out weighed any fuel consumption concerns I had previously .
I think the main reason folks do this is because of driveline slop which ultimately becomes problematic due to partial binding of he whole system leading to a failure , I wish we people all possessed a hard core mechanical sooth sayer like knowledge , at the exacting moment when the individual makes their misguided decision based on an uneducated fix that they may have read or had heard about .
This will and happen perpetually also as this kind of mod is determined on a personal & emotional conception .
Considering all the associated affordable aftermarket parts that are available .
Maintaining a vehicle in a cycle of perpetuation ,will always have its pros and cons . I have a firm attritional belief in all my perpetual maintenance on my most important work rest and play asset, the vehicle , my maintenance beliefs were all hard learned, as I drove boxes of turd for many years with very poor maintenance management & whilst not by being influenced by others I just believed I knew better.
For myself and a lot of others , perpetually maintaining a vehicle or boat or trailer is half the fun of ownership , having to make those all important decisions to either upgrade ,modify ,or repair ,replace , whilst Juggling an almost non existent budget, Ooooohhhaaarrrrgh the joy .
Sometimes wifey can tell when I try to pull a swifty over her to hand over our hard earned ,and ( want) to upgrade and purchase my 35” tyres instead of the (need) to replace the clutch, we all have these absolute requirements at the time ,even if it’s painstakingly obvious it’s not the right decision at the time.
Love the non biased content ,
I think your right , People just like the ability to choose and have options when they want . It’s a sense of freedom. And most people like me dive on dry Tarmac. That occasionally has adverse conditions such as deep snow and then occasionally drive off road
Andrew you are 100% correct. I have both. 2002 GM 3500 pick up DRW part time, and 2005 Hummer H2 fulltime four wheel drive. the Hummer H2 drives and handles better both on and off road than the 500 LBS. heavier 3500 and both get the same MPG.
I love my full time Awd Discovery 2! With locking center diff.
Same, best off road vehicle available
@@psiwog I added front and rear air lockers, and regeard the diffs. Sitting on 35s its pretty unstoppable!
@@krover01 do you have any videos on your beast mate ?
@@psiwog click on his picture, will take you to his channel