I've searched and watched almost every video on UA-cam about how AWD works over the past few days, and only Weberauto gave me a clear explanation. thank you very much! This video is the same as all Weberauto videos I've seen before, each one is a forever classic.
One of the most useful and well put together videos on the internet. Full stop. Taking a complex subject and making it simpler. Great teacher. I have learnt so much.
THIS IS WHAT I HAVE BEEN MISSING. THIS REALLY CLEARS THINGS UP. I REBUILT A 6F35 TRAND IN MY ESCAPE AND PULLED THE PTO WHILE DOING IT AND COULD NOT FOR THE LIFE OF ME FIGURE OUT WHAT ACTUATES THE 4WD. THIS IS CONFUSIN AS 09 ESCAPES COME IN AWD AND 4WD AND THE PTO'S AND TRANSMISSIONS ARE EXACTLY THE SAME. NOW I KNOW THE ACTION IS ALL AT THE REAR OF THE VEHICLE.
I rarely have enjoyed such a clear and well done video explaining mechanics in trully simple and understandable way ! I myself am a teacher (professor..but in forest entomology...hence that bee flying in at 11:18 :-) but love to understand my vehicle...and finally, after reaching this video I got a really clear picture and answers to my understanding of an AWD ! Not being a native English speaker myself, it even adds to a brilliantly done video (I believe) which obviously stirred quite an attention (positive comments(questions). Thanks a lot for teaching on line. That's what education is all about - to grab a student's attention ! Perfect !
Thank you very very much Prof. Kelly. You are my life time the best teacher who show me the kindness and clear explanation about automotive technology which I have to imitate your accurate but easy to follow and understand teaching method to my friends and customer.
This video summarizes what 'compact SUVs' a.k.a. crossovers are capable of. The drivetrain components on these crossovers are too fragile for serious off-road use (barring occasional dirt/gravel trails). Thank you for this anatomy lesson, Professor John D. Kelly
Well you made Crossover AWD easy to understand and only needed to watch the video one time . Great teaching tool for kids in Autoshop . I'm a Heavy Duty Truck and Coach / Heavy Equipment Tech that's about to downsize from my GMC Yukon to a AWD Crossover Now that I understand the power transfer to rear and see that it's somewhat heavier then visioned , I will add AWD to my search list . Great Video !
Thank you sir! Wonderful explanation. I just bought my first sideways engine (transverse) AWD vehicle and I needed to understand how the drive train is different than my so called 4x4 truck. So my 2014 AWD Volvo XC90 has transaxle, open diff in front and open diff in rear, but is sometimes has both front and rear axles drive via the PTU "Bevel Gear" and Haldex clutch assembly on the front to rear propeller shaft.
the ratio of likes to unlikes just shows the quality of video you have made here sir. That was a really good and handy explanation. I just saw the channel, I hope there's more on the power trains of of cars.
@@woodennecktie This video has over 200,000 views and only 60 dislikes (0.03%). As a professor of automotive technology, I understand that there are many different learning styles, levels of experience, and levels of knowledge. I made these videos for my college students who have limited knowledge and experience. I understand that someone who thinks they may already know how a certain system works may find my presentations boring or too basic.
So we have a different aprouch in whats basic and whats detail . Thats okay we teach crane operators, And the first thing we explain is the input and output of a system... Than we go into the details , sitting on a stool is not a way to explain subjects of any kind
I have a 2002 Pontiac 4T60E that I have rebuilt, when I first start out it will shift once into second, then will seem as though it skips and goes into 3rd gear then will come back into 2nd gear, after watching all of Ur videos Iam sure U can help me diagnose this problem, I have asked several other people and haven't come up with a good answer, Iam so impressed with Ur classes and would like to be a little younger so I could be enrolled in Ur classes since like I have stated I learn so,etching every time I watch one of Ur classes, This auto is equipped with a 3,1 eng. And is a Grand Prix SE, during the overhaul of the Trans I replaced all the clutches and bands and seals and cleaned the valve body
Hi John, thanks a lot for the great video. you're such a great teacher, explaining things in a step-by-step, crystal clear manner. i've been watching a lot of your other videos to fulfill my curiosity and learned heaps from. looking forwards for your future publishes, cheers.
Thank you for this very informative video. I am a retired auto body technician and I am always trying to learn as much as I can with regards to AWD ,PTU units etc. Your video was very helpful and I have save it for future reference. Thanks again. Canada
working on my 2002 ford escape towed away without dollies and was mystified why I have no rear wheel drive at any time even when I flip the switch to 4x4. took apart the rear dif. and discovered the clutch pack with electronic solenoid attached to the front. I get it now...I have to ensure the solenoid is working to compress the pack. Thanks for posting this as I have been searching for days to validate what was in my mind. Great learning video!
De años el mejor explicado video que he visto en UA-cam sobre estos temas , me distraía el estar buscando el botón para suscribirme excelente trabajo en esta clara explicación gracias desde CDMX.
That was a terrific video, I had some questions on how my Highlander AWD Transmission got the power to the rear wheels and you answered them for me. THANKS
These videos ar the best. It's also pretty neat to see that toyota is still using the same bolt pattern with the power transfer unit/transfer case. I have 1996 st205 and every GT-four before that had also the same bolt pattern. That ring and pinnion gear has shrunk alot compared to GT-four's.
I like the style used in the Honda Pilot or Acura MDX where the main Final Drive has 2 sets of Ring Gears, The secondary connects to a small Input shaft that goes to a Transfer Case with its own Ring and Pinion for the Propeller shaft.. Its lighter, stronger and both front axle shafts remain the same size..
Thanks for your feedback. I am not sure it is any lighter weight with the extra components inside the transaxle. The Honda system operates just like the system in this video; however, it uses different components to accomplish it. It still drives the rear driveshaft off the the transaxle differential case. The Acura systems with all of the variations of SH-AWD is also similar, but with a more advanced rear drive module for left and right rear wheel speed controls.
WeberAuto Based on the information presented, I was able to save thousands by removing the drive shaft and eliminating AWD feature by taking the pinion gear from the transfer case. Ultimately the 2005 Nissan Murano's AWD capabilities are very pricey to repair so if you are not in need of all wheel drive start eliminating the cancer and save that money for the transmission God forbid! Thanks again for the awesome succinct video my friend!
Thank you for your very informative videos! This is very similar yet very different to how Celica GT4 system works (particularity ST205 chassis). Interesting part is that unlike viscous/similar coupling at the rear differential the GT4 uses full central differential in the centre with a viscous centre, thus giving true all-time 4WD system with 50/50 torque split. This system in my opinion is far better than the typical crossover system. Meanwhile Subaru system is even better in regards that it uses planetary gear set with mechanical LSD and electromechanical LSD (two separate units) for the centre differential, specifically the DCCD variant that comes in Impreza WRX STI. I have/had pleasure owning both vehicles and I find very amusing when I go passed stuck crossover/SUV vehicles like RAV4 and similar on a beach (they seem to constantly switch between spinning a front wheel, and two diagonal wheels). I guess having LSD in front (excl. ST205) centre and rear with all time 4WD works much better than the gimmick system with viscous/electromechanical/hydraulic coupling that these crossover/SUV vehicles have.
hellow Mr killy l am wathing moste of your shows I like it so thank you . .sorry bad English... مرحبا استاد حون كلي انا اتابع معظم شروحك واحبها شكرا too mutch
John, you are amazing!! I am a auto Teacher in Canada. The videos you make after hours when youth gone are are amazing. I am just wondering. Are you in a wheel chair? It doesn't matter if or not. Your knowledge blows me away. I am learning and love it. Peace....
+MonteSBC400 Thank you! Yes, I am in a wheelchair now. Muscular Dystrophy is slowly causing me to loose all my strength. Luckily I can still work in a field I love. Take Care.
So looking at my Service manual for ford Maverick with AWD it uses a dog clutch inside the PTU to either engage or disengage the rear drive shaft from turning at all. Then has a clutch pack in the rear differential with ability to send power to either left or right axle shafts . So this way the drive shaft isn't always turning saving gas. Plus to send more power to a axle/wheel that has more traction better driving the car.
Thanks for the video, it really has me appreciating just how awesome the symplicity of my Subaru XV Crosstrek's Subaru Symmetrical All-Wheel Drive, specifically, the Continuous AWD system that actually maintains a true mechanical connection between the front and rear differentials on manual transmission (technically a manual transaxle) models. Unlike most crossovers that have some sort of electronic system to manage front-to-rear torque distribution, the Continuous AWD of manual transaxle models has a simple viscous coupling center differential. Though some may consider this system quite crude, I'm very satisfied with its ability to react in demanding spirited driving conditions as well as off-road driving.
If I'm not mistaken, the power for the rear wheels is taken from one side of the front wheel axle which itself takes power through an open differential. In this case what would happen if the other from wheel will lose traction with most of the power going to that wheel rather than to the other front wheel with good traction and therefore not to the rear wheels when they are most needed.
+Игорь Врублевский Hi, it only looks like it takes power from one side of the front wheel axle, but it is actually directly connected to the front differential case (not the side gears or axle shafts). This means that it always has power regardless of which front wheel has traction. The rear driveshaft always had power available to it or from it to the rear differential. Good question! Thanks for watching.
Kia sorento my first brand new vehicle and awd is really just two wheel drive until the other wheels are needed .......and I thought it was a continuous 60/40 split amazing video 😢
Hello John I am Brazilian and I found your video very interesting. Just out of curiosity here in Brazil the auto industry like to invent a little. In our market, automakers sell Crossover vehicles as if they were SUVs, that is, they do a Marketing of new trends, which I think is wrong. And these cars sold as SUVs are quite expensive. Olá John sou brasileiro e achei seu vídeo muito interessante. Apenas por curiosidade aqui no Brasil a indústria automobilística gostam de inventar um pouco. Em nosso mercado as Montadoras vendem veículos Crossovers como se fossem SUV´s, ou seja, fazem um Marketing de novas tendências o que eu acho errado. E esses carros vendidos como SUV´s são bem caros.
Great video... I wish i lived close to your shop, you seem to know about about what you do, I have an issue with on AWD saturn vue that NONE of my local mechanics can figure out.
Thank you for the video. Just got a 2007 RAV4 with a push button. For locking differential. What I got from your vid is the rear differential. Is turning. But not pushing. The weight of vehicle. When slips in any of the wheels the 4x4 engages?
Thank you for this - excellent explanation and far better than even a Toyota service advisor or salesperson has been able to provide. Are you able to confirm my 2011 Venza 3.5 AWD applies power to the rear wheels on initial acceleration no matter the road conditions as well as during periods of front wheel spin? It's another question I get different answers to at Toyota depending on the day and person I'm talking to... Also... The other question that mystifies me a bit is why don't they put the rear wheel clutch pack at the front of the drive shaft? That way you're not wasting energy and fuel spinning a driveshaft for nothing? Maybe a space issue or suddenly loading up that long shaft with torque would stress those multiple joints too much.....
Answering your second question - if clutch was at front then in 2WD mode whole drive shaft would be powered by rear wheels. That would probably cause bigger loss of energy then powering it by the engine. The solution is to use two clutch-packs (front and back) like in Jeep Renegade or Quattro Ultra but then the drive shaft must be speeded up from a standstill before it can transfer power to the back - that's complicated and takes time...
Much of this is down to European construction and use regulations that state that at all times under braking the rear wheels must not lock up before the front. These were draughted before ABS was common. VW had lots of experience with AWD systems using differentials in the Quatro and tried to apply the same in the Golf. But the AWD system added drag to the lightly loaded rear wheels causing them to sometimes lock up first under braking. So they deleted the centre diff and added an automatic clutch that disengaged the rear wheels under braking, the Haldex unit. This has become the norm for part time AWD cars derived from FWD units, It's cheaper. However a Haldex unit is not really needed on well balanced cars like the Subaru or bigger SUVs.
Very well done video. I just purchased a 2021 Kia Seltos awd. It looks to be similar to the system you explained. It has a hydraulic pump to activate the clutch pac located before the rear differential. Is it practical to service/drain and refill the oil from that clutch assembly say at the same time as servicing the PTU and rear differential.
My 2008 Highlander AWD has a noisy rear drive shaft pinion bearing inside the propeller shaft housing of the PTU. I verified this with a four channel noise finder while driving over 30MPH. One sensor on PTU housing, one on the propeller shaft housing of the PTU, one on the mid-point propeller shaft coupling and one on the rear diff. The sensor on propeller shaft housing of the PTU was by far the loudest. Every shop I spoken with wants to remove the entire transmission and replace the PTU with a used one. $4000 at least. Can't the propeller shaft be removed from housing, the housing removed from the PTU to access the bad bearing and replace it with the trans still in the car?
Do you have any videos detailing the viscous coupler/ magnetic clutch you talk about at the 22 minute mark. I have a 2011 Sienna Limited AWD and I think it's gone as it makes a loud hydraulic whine as it's driven. as you speed up the pitch gets louder. I've seen some forums say Toyota says you have to replace the entire unit but some others say you can disassemble it and if you can find the part number replace the 2 large bearings which are the fail point. Any of your great insight is appreciated!
@@Sig220Euro ppl need change gear oil in these units every 50k mis max.. engineers have told me. In our Lincoln SUVs AWD i follow this maintenance with great success getting high mis an zero failure.
Trying to wrap my head around this regarding AWD operation in a Lexus LS 460 L COMPARED TO SAY AN AWD system used in my 97 Land Cruiser. Specs tell me that the same 8 speed trans for the LS is also used in the late model Land Cruiser.
The AWD system on your LS is similar, but different than the 97 Land Cruiser. The LS 460 uses the AA80E while the later model Land Cruiser uses the AE80F 8-speed transmission. They are almost identical, but the newer model is refined and beefed up a little more.
Great job now I have a Lincoln MKS all-wheel-drive and the PTU is whining a little bit 80,000 miles and Ford told me $2000 to replace I want back again today and said why can’t you just suck out the oil and put new gear oil in and he said it’s like an old transmission you take the oil out it just causes more problems do you think this is true or should I try to suck the oil out I could barely hear the whine
I've searched and watched almost every video on UA-cam about how AWD works over the past few days, and only Weberauto gave me a clear explanation. thank you very much! This video is the same as all Weberauto videos I've seen before, each one is a forever classic.
One of the most useful and well put together videos on the internet. Full stop. Taking a complex subject and making it simpler. Great teacher. I have learnt so much.
THIS IS WHAT I HAVE BEEN MISSING. THIS REALLY CLEARS THINGS UP. I REBUILT A 6F35 TRAND IN MY ESCAPE AND PULLED THE PTO WHILE DOING IT AND COULD NOT FOR THE LIFE OF ME FIGURE OUT WHAT ACTUATES THE 4WD. THIS IS CONFUSIN AS 09 ESCAPES COME IN AWD AND 4WD AND THE PTO'S AND TRANSMISSIONS ARE EXACTLY THE SAME. NOW I KNOW THE ACTION IS ALL AT THE REAR OF THE VEHICLE.
I rarely have enjoyed such a clear and well done video explaining mechanics in trully simple and understandable way ! I myself am a teacher (professor..but in forest entomology...hence that bee flying in at 11:18 :-) but love to understand my vehicle...and finally, after reaching this video I got a really clear picture and answers to my understanding of an AWD ! Not being a native English speaker myself, it even adds to a brilliantly done video (I believe) which obviously stirred quite an attention (positive comments(questions). Thanks a lot for teaching on line. That's what education is all about - to grab a student's attention ! Perfect !
Thank you very much!
Thank you very very much Prof. Kelly. You are my life time the best teacher who show me the kindness and clear explanation about automotive technology which I have to imitate your accurate but easy to follow and understand teaching method to my friends and customer.
All of Prof. Kelly's videos are thoughtful and very instructive. I am enjoying them very much! Thank you!
This video summarizes what 'compact SUVs' a.k.a. crossovers are capable of. The drivetrain components on these crossovers are too fragile for serious off-road use (barring occasional dirt/gravel trails).
Thank you for this anatomy lesson, Professor John D. Kelly
Well you made Crossover AWD easy to understand and only needed to watch the video one time . Great teaching tool for kids in Autoshop . I'm a Heavy Duty Truck and Coach / Heavy Equipment Tech that's about to downsize from my GMC Yukon to a AWD Crossover Now that I understand the power transfer to rear and see that it's somewhat heavier then visioned , I will add AWD to my search list . Great Video !
Thank you for not only explaining, but also showing us how the system works.
Thank you
Thank you sir! Wonderful explanation. I just bought my first sideways engine (transverse) AWD vehicle and I needed to understand how the drive train is different than my so called 4x4 truck. So my 2014 AWD Volvo XC90 has transaxle, open diff in front and open diff in rear, but is sometimes has both front and rear axles drive via the PTU "Bevel Gear" and Haldex clutch assembly on the front to rear propeller shaft.
Glad it helped. Thanks for watching. Haldex is used by many vehicle manufacturers
the ratio of likes to unlikes just shows the quality of video you have made here sir. That was a really good and handy explanation. I just saw the channel, I hope there's more on the power trains of of cars.
what a great introduction to CUV AWD - much appreciated
You're a remarkable teacher! I've learned and connected so many dots because of this video, thank you!
i realy do not know what to say , there is not a more confusing explanation to such simple concept , this man is genious in making it difficult
Thanks for watching anyway
so you get my point , thanks for reacting .
@@woodennecktie This video has over 200,000 views and only 60 dislikes (0.03%). As a professor of automotive technology, I understand that there are many different learning styles, levels of experience, and levels of knowledge. I made these videos for my college students who have limited knowledge and experience. I understand that someone who thinks they may already know how a certain system works may find my presentations boring or too basic.
So we have a different aprouch in whats basic and whats detail . Thats okay we teach crane operators, And the first thing we explain is the input and output of a system... Than we go into the details , sitting on a stool is not a way to explain subjects of any kind
@@woodennecktie I am in a wheelchair
I have a 2002 Pontiac 4T60E that I have rebuilt, when I first start out it will shift once into second, then will seem as though it skips and goes into 3rd gear then will come back into 2nd gear, after watching all of Ur videos Iam sure U can help me diagnose this problem, I have asked several other people and haven't come up with a good answer,
Iam so impressed with Ur classes and would like to be a little younger so I could be enrolled in Ur classes since like I have stated I learn so,etching every time I watch one of Ur classes,
This auto is equipped with a 3,1 eng. And is a Grand Prix SE, during the overhaul of the Trans I replaced all the clutches and bands and seals and cleaned the valve body
Thats what I needed to know. Thank you sir, for such detailed information. Very good job indeed.
Thank you!
Hi John, thanks a lot for the great video. you're such a great teacher, explaining things in a step-by-step, crystal clear manner. i've been watching a lot of your other videos to fulfill my curiosity and learned heaps from. looking forwards for your future publishes, cheers.
+larry li Thank you!
Respect for the amount of energies and time put on this video
Thank you for this very informative video. I am a retired auto body technician and I am always trying to learn as much as I can with regards to AWD ,PTU units etc. Your video was very helpful and I have save it for future reference. Thanks again. Canada
Thank you!
working on my 2002 ford escape towed away without dollies and was mystified why I have no rear wheel drive at any time even when I flip the switch to 4x4. took apart the rear dif. and discovered the clutch pack with electronic solenoid attached to the front. I get it now...I have to ensure the solenoid is working to compress the pack. Thanks for posting this as I have been searching for days to validate what was in my mind. Great learning video!
Thank you. I am glad it was helpful
De años el mejor explicado video que he visto en UA-cam sobre estos temas , me distraía el estar buscando el botón para suscribirme excelente trabajo en esta clara explicación gracias desde CDMX.
Thank you!
You have taken to another world, amazing knowledge even engineers could not understand the mechanism.Thanks for the information
Glad it was helpful!
hi sir, the way u r discribing is very easy to understand, thanks for giving this type of great lessons....
+bala chandran Thank you for watching!
Fully explained. Simply brilliant explanation. Many thanks for that.
These videos are amazing I really appreciate the effort you put into these.
Thank you
John, your video in these units cleared up a lot of mystery for me. Thank you!
Glad to help. Thanks for watching
That was a terrific video, I had some questions on how my Highlander AWD Transmission got the power to the rear wheels and you answered them for me. THANKS
Thank you!
My pleasure , that's a lot of work you put in to produce the video, thanks again. - L
John watching this in 2021 I very much enjoy watching your videos I've learned and lot THANKS
You are very welcome. Thanks for watching
Excellent tutorial as always Sir ! Thank you for your lucid explanations , as always.
My God I love to watch your teachings on Power trane , very good work Sir... Steve in Canada
Thank you very much!
Great videos-Thanks from an old mechanic(technician)!!!
john james Thank you!
Knowledgeable and well explained, easy to understand and follow. You made this look easy. Heck with manuals, just come to this channel.
Thanks for watching
Best description on a Toyota AWD system so far. Thanks!
Thank you!
WOW. Thank you for the tour. Well presented and recorded. Subscribed.
Thank you Sir...this is the Suzuki SX4 AWD system in a nut shell. Great video!
These videos ar the best. It's also pretty neat to see that toyota is still using the same bolt pattern with the power transfer unit/transfer case. I have 1996 st205 and every GT-four before that had also the same bolt pattern. That ring and pinnion gear has shrunk alot compared to GT-four's.
Thanks for the NVH class today. learned a few things on the pico scope
+Piston Slap Thank you!
I like the style used in the Honda Pilot or Acura MDX where the main Final Drive has 2 sets of Ring Gears, The secondary connects to a small Input shaft that goes to a Transfer Case with its own Ring and Pinion for the Propeller shaft.. Its lighter, stronger and both front axle shafts remain the same size..
Thanks for your feedback. I am not sure it is any lighter weight with the extra components inside the transaxle. The Honda system operates just like the system in this video; however, it uses different components to accomplish it. It still drives the rear driveshaft off the the transaxle differential case. The Acura systems with all of the variations of SH-AWD is also similar, but with a more advanced rear drive module for left and right rear wheel speed controls.
Clear and complete explanation! Thank you 🙏
Thank you
Love this tutorial. Thank you so much.
I bought a Ford police interceptor sedan (Taurus) and was curious how these systems worked, being fwd biased and such. Very informative.
Thanks for watching
Masterful presentation. Seeking to bypass the was on murano.. I think I will start by disabling the Clutch Permanently.
Thank you!
WeberAuto Based on the information presented, I was able to save thousands by removing the drive shaft and eliminating AWD feature by taking the pinion gear from the transfer case. Ultimately the 2005 Nissan Murano's AWD capabilities are very pricey to repair so if you are not in need of all wheel drive start eliminating the cancer and save that money for the transmission God forbid! Thanks again for the awesome succinct video my friend!
thanks for sharing, such a great video. Indeed Subaru transmission review would be awesome :)
Fascinating! Thank you, Professor Kelly!
Glad you enjoyed it!
@@WeberAuto My favourite channel! 👍🏻 I hope you and your family are well.
Thank you for your very informative videos!
This is very similar yet very different to how Celica GT4 system works (particularity ST205 chassis). Interesting part is that unlike viscous/similar coupling at the rear differential the GT4 uses full central differential in the centre with a viscous centre, thus giving true all-time 4WD system with 50/50 torque split. This system in my opinion is far better than the typical crossover system.
Meanwhile Subaru system is even better in regards that it uses planetary gear set with mechanical LSD and electromechanical LSD (two separate units) for the centre differential, specifically the DCCD variant that comes in Impreza WRX STI.
I have/had pleasure owning both vehicles and I find very amusing when I go passed stuck crossover/SUV vehicles like RAV4 and similar on a beach (they seem to constantly switch between spinning a front wheel, and two diagonal wheels). I guess having LSD in front (excl. ST205) centre and rear with all time 4WD works much better than the gimmick system with viscous/electromechanical/hydraulic coupling that these crossover/SUV vehicles have.
Thanks for your great feedback! There are many variations of "AWD", most people do not know the differences.
Appreciate the information shared through this video. Thank you!
Thank you
Thank you that was great...learned a lot..Professor you do a fantastic job! Decision now buy a Ridgeline with FWD or AWD!
Thank you
This clears up a lot of confusion thanks.
Thank you!
Thank you for making this video and sharing it for free.
amrit351 Thank you for watching.
Another informative session downloaded to my memory, Thank you.
Thank you!
This was a great tutorial, kudos to your work, this video made my day, thanks man ❤️❤️. I always wondered how AWD works and here's the answer
Your videos are very informative! Thank you sir!
Thanks for watching!
Very much appreciated for this video. Liked and subbed. Was looking for exactly this!
Thank you!
hellow Mr killy l am wathing moste of your shows I like it so thank you .
.sorry bad English...
مرحبا استاد حون كلي انا اتابع معظم شروحك واحبها شكرا too mutch
+خالدمحمد الرحيلي Thank you for watching!
What a wonderfully made video. Marvelous! :-)
Thank you
You answered EVERYTHING!!!.......Thank you!
Thank you!
What about when you getting noise from their what cause it
Very informative. Enjoyed it, well done sir
Thank you!
I have a Renault Koleos, (Nissan X Trail AWD drive train) and I wondered how it worked... now I do :-)
John, you are amazing!! I am a auto Teacher in Canada. The videos you make after hours when youth gone are are amazing. I am just wondering. Are you in a wheel chair? It doesn't matter if or not. Your knowledge blows me away. I am learning and love it. Peace....
+MonteSBC400 Thank you! Yes, I am in a wheelchair now. Muscular Dystrophy is slowly causing me to loose all my strength. Luckily I can still work in a field I love. Take Care.
Excellent video! Well done. Thanks for your effort.
Thank you!
Super explenation. Thankyou very much!
Thank you
An advantage of the overdriven propeller shaft is that it can be thinner to handle a given amount of torque from the transaxle.
Well done, really informative. Subscribed right away.
Thank you!
Very informative video. Thank you. Helped me explain a lot to my son :)
Thank you! I am glad it was helpful
I love ALL your videos, you are doing great job!!
Thank you!
Great explanation professor!
It clears so many doubts, thanks a lot.
Thank you!
So looking at my Service manual for ford Maverick with AWD it uses a dog clutch inside the PTU to either engage or disengage the rear drive shaft from turning at all. Then has a clutch pack in the rear differential with ability to send power to either left or right axle shafts . So this way the drive shaft isn't always turning saving gas. Plus to send more power to a axle/wheel that has more traction better driving the car.
Thanks for the video, it really has me appreciating just how awesome the symplicity of my Subaru XV Crosstrek's Subaru Symmetrical All-Wheel Drive, specifically, the Continuous AWD system that actually maintains a true mechanical connection between the front and rear differentials on manual transmission (technically a manual transaxle) models. Unlike most crossovers that have some sort of electronic system to manage front-to-rear torque distribution, the Continuous AWD of manual transaxle models has a simple viscous coupling center differential. Though some may consider this system quite crude, I'm very satisfied with its ability to react in demanding spirited driving conditions as well as off-road driving.
Thanks for your feedback!
Now i know how. Great explanation, thank you so much sir. God bless you.
Wow...Thanks for your amazing explanation!
Thank you!
Thank you you sir you explain it very well. Thanks once again.
Thank you!
Thanks for another great explanation
+Kaktus Jack Thank You!
If I'm not mistaken, the power for the rear wheels is taken from one side of the front wheel axle which itself takes power through an open differential. In this case what would happen if the other from wheel will lose traction with most of the power going to that wheel rather than to the other front wheel with good traction and therefore not to the rear wheels when they are most needed.
+Игорь Врублевский Hi, it only looks like it takes power from one side of the front wheel axle, but it is actually directly connected to the front differential case (not the side gears or axle shafts). This means that it always has power regardless of which front wheel has traction. The rear driveshaft always had power available to it or from it to the rear differential. Good question! Thanks for watching.
+WeberAuto Now I understand, Thanks a lot for your great videos!
Kia sorento my first brand new vehicle and awd is really just two wheel drive until the other wheels are needed .......and I thought it was a continuous 60/40 split amazing video 😢
Thank you!
Hello John I am Brazilian and I found your video very interesting. Just out of curiosity here in Brazil the auto industry like to invent a little. In our market, automakers sell Crossover vehicles as if they were SUVs, that is, they do a Marketing of new trends, which I think is wrong. And these cars sold as SUVs are quite expensive.
Olá John sou brasileiro e achei seu vídeo muito interessante. Apenas por curiosidade aqui no Brasil a indústria automobilística gostam de inventar um pouco. Em nosso mercado as Montadoras vendem veículos Crossovers como se fossem SUV´s, ou seja, fazem um Marketing de novas tendências o que eu acho errado. E esses carros vendidos como SUV´s são bem caros.
great video as always!
Thank you!
Beautiful explained
Thank you for best information
You are welcome
Great explanation! Thank you!
Great video... I wish i lived close to your shop, you seem to know about about what you do, I have an issue with on AWD saturn vue that NONE of my local mechanics can figure out.
Thank you for the video. Just got a 2007 RAV4 with a push button. For locking differential. What I got from your vid is the rear differential. Is turning. But not pushing. The weight of vehicle. When slips in any of the wheels the 4x4 engages?
True! Thanks for watching
Thank you for this - excellent explanation and far better than even a Toyota service advisor or salesperson has been able to provide. Are you able to confirm my 2011 Venza 3.5 AWD applies power to the rear wheels on initial acceleration no matter the road conditions as well as during periods of front wheel spin? It's another question I get different answers to at Toyota depending on the day and person I'm talking to... Also...
The other question that mystifies me a bit is why don't they put the rear wheel clutch pack at the front of the drive shaft? That way you're not wasting energy and fuel spinning a driveshaft for nothing? Maybe a space issue or suddenly loading up that long shaft with torque would stress those multiple joints too much.....
Answering your second question - if clutch was at front then in 2WD mode whole drive shaft would be powered by rear wheels. That would probably cause bigger loss of energy then powering it by the engine. The solution is to use two clutch-packs (front and back) like in Jeep Renegade or Quattro Ultra but then the drive shaft must be speeded up from a standstill before it can transfer power to the back - that's complicated and takes time...
Tank you for this video information
The video quality of your videos is outstanding. What sort of camera and equipment are you using?
Certified Transmissions Thank you! I am using a 5 year old Canon HD digital Camcorder Model HFS200. It still works great!
Thank you very educational!
Thank you!
Much of this is down to European construction and use regulations that state that at all times under braking the rear wheels must not lock up before the front. These were draughted before ABS was common. VW had lots of experience with AWD systems using differentials in the Quatro and tried to apply the same in the Golf. But the AWD system added drag to the lightly loaded rear wheels causing them to sometimes lock up first under braking. So they deleted the centre diff and added an automatic clutch that disengaged the rear wheels under braking, the Haldex unit. This has become the norm for part time AWD cars derived from FWD units, It's cheaper. However a Haldex unit is not really needed on well balanced cars like the Subaru or bigger SUVs.
Thanks for your feedback!
Very well done video. I just purchased a 2021 Kia Seltos awd. It looks to be similar to the system you explained. It has a hydraulic pump to activate the clutch pac located before the rear differential. Is it practical to service/drain and refill the oil from that clutch assembly say at the same time as servicing the PTU and rear differential.
Thanks for watching
Such a great video!!! 👏👏👏
Thank you!
The content is great thanks
So theoretically if I put an open differential on the rear, I wouldn't a cluth pack or fluid coupler in the middle of the propeller shaft?
Great video!
Thank you!
Great video, thanks again
great information video
Thank you!
My 2008 Highlander AWD has a noisy rear drive shaft pinion bearing inside the propeller shaft housing of the PTU. I verified this with a four channel noise finder while driving over 30MPH. One sensor on PTU housing, one on the propeller shaft housing of the PTU, one on the mid-point propeller shaft coupling and one on the rear diff. The sensor on propeller shaft housing of the PTU was by far the loudest. Every shop I spoken with wants to remove the entire transmission and replace the PTU with a used one. $4000 at least. Can't the propeller shaft be removed from housing, the housing removed from the PTU to access the bad bearing and replace it with the trans still in the car?
Do you have any videos detailing the viscous coupler/ magnetic clutch you talk about at the 22 minute mark. I have a 2011 Sienna Limited AWD and I think it's gone as it makes a loud hydraulic whine as it's driven. as you speed up the pitch gets louder. I've seen some forums say Toyota says you have to replace the entire unit but some others say you can disassemble it and if you can find the part number replace the 2 large bearings which are the fail point. Any of your great insight is appreciated!
Sorry, I do not have any information like that.
Thanks, appreciate the reply either way!
PTU unit or transfer prob bad!
@@Sig220Euro ppl need change gear oil in these units every 50k mis max.. engineers have told me. In our Lincoln SUVs AWD i follow this maintenance with great success getting high mis an zero failure.
Trying to wrap my head around this regarding AWD operation in a Lexus LS 460 L COMPARED TO SAY AN AWD system used in my 97 Land Cruiser. Specs tell me that the same 8 speed trans for the LS is also used in the late model Land Cruiser.
The AWD system on your LS is similar, but different than the 97 Land Cruiser. The LS 460 uses the AA80E while the later model Land Cruiser uses the AE80F 8-speed transmission. They are almost identical, but the newer model is refined and beefed up a little more.
Can you do a video of the clutch fluid service on 2018 awd traverse? It takes pentosin chf11s for clutch fill (similar to a haldex service)thank you.
Excellent video. I was curious how the front PTU connects to the transaxle
Thank you
WeberAuto do you think you could do a video on the two speed PTUs found in the Jeep Cherokee TrailHawk?
@@MichaelMiller-rg6or I have been waiting to get my hands on them. There are three different versions.
Great job now I have a Lincoln MKS all-wheel-drive and the PTU is whining a little bit 80,000 miles and Ford told me $2000 to replace I want back again today and said why can’t you just suck out the oil and put new gear oil in and he said it’s like an old transmission you take the oil out it just causes more problems do you think this is true or should I try to suck the oil out I could barely hear the whine
Mantap kali bang pemjelasan nya...