How to: Test & replace overrunning alternator pulley (OAP) Ford, VW, Audi etc
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- Опубліковано 9 лют 2025
- Adventures in removing and replacing an overrunning alternator pulley. Short version: use an impact wrench for removal! But you can try with hand tools. Featured is a Visteon generator with an Ina pulley using a 33-spline removal tool.
Removing the alternator: • How to: Remove alterna...
You will need:
New pulley to suit. Check size & slip/thread directions. Try searching Amazon ~ US: amzn.to/2lvN0H6 | UK: amzn.to/2lvSVfr
Specialist pulley tool to suit your pulley. Try Amazon US: amzn.to/2mAVNrm | UK: amzn.to/2lygnZl
Long drive bit to suit alternator shaft, either hex or torx. Try Amazon US: amzn.to/2l1BAuG | UK: amzn.to/2mAYzwM
A good ring spanner to fit the pulley tool, and bench vice or extension pipe
Torque wrench with reversible torque suitable for ~85 NM
Good penetrating oil. Amazon US: amzn.to/2lylatN | UK: amzn.to/2lw25sl
(Using the above links helps support my channel and is appreciated!)
Amazon links (more info in desc):
New pulley to suit, try ~ US: amzn.to/2lvN0H6 | UK: amzn.to/2lvSVfr
Pulley tool to suit ~ US: amzn.to/2mAVNrm | UK: amzn.to/2lygnZl
Long drive bit to suit ~ US: amzn.to/2l1BAuG | UK: amzn.to/2mAYzwM
Penetrating oil ~ US: amzn.to/2lylatN | UK: amzn.to/2lw25sl
Hl
What is the difference between OAP and OAD???
Can we see the difference with eyes???
Can we replace an OAP pulley with an OAD pulley????
Very well put together tutorial delivered in a calm way with no music - you see it can be done
So refreshing to see a video where things don't always go to plan and smoothly. Great video.
Can’t thank you enough. I almost bought a new alternator because it was making that popping noise. I took the belt off and sure enough it was seized. HUGE SAVINGS! Thanks again.
This is definitely the most informative and well explained DIY car maintenance video I’ve ever watched. Thank you.
You bro, I had never seen what kind of connection this was and I’ve been searching and searching that. I finally saw your video and that’s exactly what mine is so thank you for doing a video. I hope the day finds you smiling
Wow..What a breath of fresh air! An intelligent, coherent and well produced how to video..Thank you..Liked & Subscribed...
I find it inspiring that Damien Lewis still works on his own car even with all his money!! Never too successful to get your hands dirty!
can anyone tell me why my 96 Jeep had a serpentine belt and a fixed idler pully ?
I owned it from 99 to 2023 replaced three belts over that time yet never touched alternator ? it was factory alternator and did not have a stupid auto.matic tensioner??
People are stupid the Mazda you buy today will have cost its purchase price in parts and labour in four years
this is because of four
cylinder crank pulses I suppose my old jeep being a six cylinder had a smoother pulse rate?
I'm really confused. What is your question
Thanks. Your video shows what a DIY person face when trying to do these type of work at home.
With another person help and strength I managed to changed the OAP from my Lancer.
went to help my mate who had his pulley bearing come apart on him we tried with the tools for 2 hrs to get it off in situ it would not budge so hes now got to remove the alternator to do it on the bench a nightmare for him on his car the joys of modern motoring so many special tools and extra hassle... nice video thanks for taking the time
update hes ended up buying a new alternator as its original and old anyway and dosent want to have any more hassle as going on holiday in it next week... but its cost him £150 for a new one complete with pully bearing
Best video on this problem..my van has been bad for years..replaced crankshaft pulley and tensioner...amazing how few people have heard of the one way clutch pulley
Excellent video!
I love that you added the INA side-by-side demonstration video of the solid pulley vs. OAP.
This was a great example of what to do and what not to do, teaching both the right and wrong way to do it.
Very informative video and great production quality as well.
That was something I didn't know about till watched this video. So, I did learn something new after all. Brilliant!
Thankyou, I have a hyundai santa fe and have put up with this for months, I found your video by accident and it was the best accident ever, thankyou for your help and knowledge 🙂🙂
Really good video. Appreciate the detailed commentary and high quality, steady camera work.
Thanks for being honest. Not always an easy job and gives an example that asking for help might be necessary.
You: "There is no real way that it can come undone on the car"
My car: "I found a real way that it can come undone while my owner drives me. Extra: the half of the tensioner roller vanished, the belt of course is now open."
Haha, so probably the freewheel function has gone and the pulley become a simple nut. Volvo V70 diesel 2002 @ 380000 miles.
Thanks for your video, now I understand better the insights and now I know what waits for me tomorrow.
An interesting addition: that morning I heard some "grasshopper" from the engine, I localized that it is the generator pulley, which traveled towards the generator first and touched it a little bit and started to make small chips, like on a lathe. I had no clue what was happening, so I went to the job, but I put 2 extra batteries into the baggage room and a start cable for every case (have some experience) . After 1 hour happened what I didn't want to happen, I prayed I can drive one hour more with the extra battery without a generator. (the battery in the car of course is near the end of life). I bought a better battery charger, so I could drive home the next day with 2 fully charged (1.5) batteries (approx 150Ah total), 2.5-3 hours, no headlights, and a few stops/engine starts.
It's like a British retro tutorial, jolly good.
Thank you for a clear graphical explanation on how the pulley works and the purpose of the pulley clutch unit which is on my Kia Sorento 2.2 turbo diesel alternator.
Yep. My tensioner was rattling like crazy and my belt warped and twisted when idling. I took the belt off and noticed a crack on the belt. I checked all the pullies including the OAP by sticking a screwdriver between the fan blades in the alternator and trying to turn the pully both ways. It locked both ways. It's gone. $98AUD for a new OAP that I install myself. I learnt how to do it from youtube hahaha. I can fix most things on my cars because of youtube.
I could listen to this guy talk forever. Reminds me of Jarvis.
I changed the pulley on my -08 Toyota Auris yesterday. I bought a 14 pieces pulley tool set from my local partstore, but non of the bits fitted. It had like a 17mm insex with a 12 or 13mm boltend on middleaxle. I just drilled down the bolthead so the 17mm insexbit fitted and simply used my Milwuakee M14 fuel to loosen it. Worked great!
Nice video. Using an impact wrench to get it loose a really good suggestion.
Very informative..including what didnt work..thanks
Outstanding video, sir! Greetings from California!!!!
Many thanks an excellent video on a little known problem! Great presentation and explanations.
Just went through all this before discovering your helpful video...typical of my luck! Hopefully others will find it useful though, much easier than working it all out from the ground up :-)
Very good video. Clear and Precise
High quality tutorial video. I'm about to upgrade my minivan's alternator and decided to add 2 new alternators.
Cheers 👍 informative, relaxed and distinct lack of drama. 🍿🍿🍿🍿🍿
Great video! Highly informative.
Always love your mondeo vids, thank you.
I managed 150k miles on my OAP...2004 54 plate Passat 1.9PD AWX. Was worse under idle, sounded pretty bad. Fitted genuine OAP and aux and A/C belts too. Happy days.
An excellent, well produced informative video. Thanks
Very well spoken, and an excellent explanation! Many thanks ;-)
This is exactly what happened in my car. Firstly it was the tensioner went bad. Replaced it with together with the belt and then surprisingly new tensioner vibrates. After that I replaced my water pump pulley because it sounds squeaking. In the process I also found the timing belt is due replacing too. After all that, tensioner still vibrates and I'm just stumped. The tricky thing about the OAP is that they don't really show any sign or symptoms of going bad. It only manifests its malfunction in other parts.
Tried to do mone this evening with tools, not a chance. Lightest dakdak with impact gun using spline socket and just a rag holding pulley and straight off. Thanks for the suggestion. I wouldnt normally use my impact on that type of repair.
I did the same, had to use about 2 ugga duggas though as dakdaks were not enough.
Heat from a MAPP burner and impact tools are a life saver in these cases :) it will save the day many times if you are doing a lot of work on cars.
thanks for the tips, it was very helpful and the video is very clear
Its a faff but with the Bosch alternator on my Bora TDI, I removed it then took the alternator rear off, then used a oil filter chain wrench to grip the rotor so I could loosen the pulley with the VW 33 point spline tool.
Well done and thanks for the education
Good morning and very easy to use the tools
Great video. It was so helpful. Thanks for sharing !
there is a third option to torque the screw , flip the 1\2 socket end the other way so you can use it for left hand thread (counter-clockwise) ... they usually have the same size , you just need to open the mechanism and flip it the other way
Excellent video and explanation. Mine just went out on our 2008 kia optima and I'd never heard about one of these or seen what it was. Not a cheap fix, mine was $1000 t repair. Now I understand it better.
what an amazing video! highly informative thank you
Very detailed information. Thank you.
Good of you to actually show what #@#& job these Pulleys can be to remove without professional tools. Most videos show them popping off easily. I've nearly always had to remove the alternator to replace the oap.
Good tips thanks Damien Lewis.
Shaft head on mine stripped to absolute bits first go, soft metal on mine
My alternator pulley is bent. Could that cause the belt to run off the pulleys to one side? I'm considering whether to replace the entire alternator or just the pulley. The car has over 300,000 miles
Excellen video thanks...👍👍👍
My advice is to use an impact wrench to get the pulley off of the alternator. The pulley is bad anyway so you don't have to worry about ruining it. Use the proper tools to get the pulley back on the alternator and torque it down to the proper torque. Using an impact wrench on the new pulley could damage it. Trying to use the 31 tooth pulley with the center allen wrench tool to get the pulley off could break the allen wrench.
Nicely done 👍💐
I was about to do mine but lost my 8mm hex. Off to the tool shop to get another one
Thanks for the video, did this cure the noise? Thanks
I don't know something hilarious about this video - shouldn't you be sipping tea in your court gardens? Fallen on hard times I guess..
Just Kidding! Lol 😆
The pulley is actually self tightening, what with the reverse thread. Like a viscous fan coupling.
Thanks for all the info and help. but i must ask, what mic are you using because it sounds great. I need one for my channel.
I have 2012 Ford Fusion with the 2.5 Duratec. Battery light always comes on within 30 seconds of startup and the idle drops for a second when it does. I actually had the battery and alternator voltage tested by a shop originally. Both are perfect and have never had charging issues. It has been doing it now for over a year actually. The strange part is the light only really started coming on like this after the headlights were left on overnight which drained the battery. I then used my jump pack to get it started. Battery light has been coming on ever since. I have also unplugged the battery to try and reset it and no change. I only recently thought about it being a worn out alternator pulley? Is it possible that a reoccurring battery light like this could just be giving a false warning? 😅🤔
I used cheap electric impact gun and worked like a charm
Yes, that's it, that's the noise.
Perfect - Thank You.
yes agreed, a locked alternator pulley makes some strange noises that are hard to locate
thank you Sir!
IVE GOT a noisy one and works fine and i tested spraying some oil around the back and it went away, could be dry bearings but I'm going to change it as I'm on 70k as they say 60-80 is around fail rate
Thanks very much
When mine went it would make a really loud screeching noise like like dry metal to metal, it started of as what sounded like a bit of belt screech then one morning the thing didnt stop screeching untill i got to the end of the road, i pulled over and took the cap off and started it up it would screech intermittently and you could clealy see the pully spinning a lot faster than the inner spindle, mine just lost its ability to grip to bring the alternator up to correct speed, its was a weird drive to the engine would pulse away with randam battey lights, mine has a vacuum pump on as well so it was also playing havoc with the brakes and turbo
For removing that kind of pulley, I used that special tool with air gum. Don't need to use lock shaft alternator.
Top job👍 Thank you
Good video thanks..
Where did you purchase your OAP pulley??
Craig. Just wondering if you can remember wether your pulley noise got worse after driving for a while and more noticeable under certain loads?
😢I just broke those thing that need M10 with 12 points but I used T50 bit 6 points so I had no choice than to remove the alternator out and there is no way than to use “ electric Wrench / IMPACT with spline 33 “, It’s done no more than 3s, Wondering why didn’t I use this method than by those manual tools it’s so hard like hell ( I’m not a mechanic)
Then I put a new INA (OAP) pulley back but I cannot use any Torque wrench either, so I shot twice with electric Wrench impact twice a second each with hope just close to torque value without break the new pulley, DONE !
I believe by running the car it will help to torque themselves 😂to the value 85NM*
It seems now is running fine without “clang weird noise “. I did replace the pulley because even after replacing the Tensioner, the weird noises and the tensioner was goggling too, the most culprit was the seized pulley’s 😂solid no clutch!
IF you don’t have any experience like me to do this but you have to, remove the alternator from the car, check the right tool for…
Or just use electric impact that we use for replacing wheels with spline, a second done !
Lesson to be learned 😅
Good vid, thanks
Hi what size splined tool was it to fit fords?
I.J.S. GROUP 301003 Данный шкив идет как взаимозаменяемый под генератор с обычной муфтой. Он имеет углубление которое есть на генераторе с обычной муфтой. т.е этот шкив можно поставить на оба вида генераторов.
If the pulley is gone,does it cause charging issues?for instance charging ok in low revs and not charging in high rev s?
Not like this. But if you suspect your alternator, test your alternator.
Allready did mate but still same issue,i think the pulley spins freely
The reason that you couldn't get the nut off was not an impact wrench. The NUT should be turning Clockwise as its reverse treaded. But as it clearly can be seen @7:32 your are turning it counter clockwise!!!
Informative
My friend you are wrong
OAP screws clockwise, on 7:32 turns the axis=shaft clockwise thus unscrewing the OAP
Here can you see another video
ua-cam.com/video/9sObuyPDZaY/v-deo.htmlsi=qj4Fh1TWUkmhC1mp
Hello Craig, you think that it was seize because that little cap was missing? Thx
It wouldn't have helped.
@@CraigsDIYThx for the reply. I saw lot of video about that pulley. How to know that it is seized? I see also that it destroy the alternator shafts because it was seized for too long. I bought one but i am now afraid to mount it.
Can we use OAD type Pulley in place of OAP?
good job
Thanks mate great video
did you change the crankshaft pully graig ? i was going to give mine a go and wizz it off with an impact but im not too sure weather it be safe enough without locking the crank
No, it requires a decent impact gun, do you just want to replace the pulley? To do timing you need the right tools. Stories on talkford.com are worth reading over, e.g. talkford.com/community/topic/158267-crankshaft-pulley-removal/
Could an overrunning pulley cause less voltage from the battery? I'm getting less than 10.5 volts
Well sure if it's completely shot and spinning free but that's unusual, normally they seize up and behave like a solid pulley while making weird noises. You need to to diagnose your alternator system and check it is the alternator to begin with. Try ua-cam.com/video/Q2AAMc9VIMo/v-deo.html
Craig's DIY Car thanks brother - I appreciate that
is it not possible to take out the pulley alone, without taking out the alternator,,,,?????????
Good vid, but you where trying to unscrew the wrong way, looking at you unscrewing at the end it is just a normal right hand thread .
BEWARE: not all these pulleys have a logical reverse thread. I have a Denso alternator and it’s a standard thread.
It depends on the configuration in the car and the drive direction.
Does an alternator pully contain a bearing
It contains a bearing
Instead of changing the pulley, the problem could just be solved by replacing the alternator right?
Replacing the thing with the pulley on it would certainly seem to replace the pulley! But if it's the pulley that's faulty, surely a bit unnecessary!
Did ya say I must of loosened for you ?.
I guess, you did hear that before ... but you could be double for Damian Lewis
Are you calling me a ginger?
I don't understand how the shop used an impact wrench to drive the splined socket with the hex nut tool in place. It's a pick you couldn't watch them undo it. I wonder if the held the splined socket as you did with a ring spanner in a vice and used the impact wrench on the hex bolt?
The point of an impact wrench is it hammers the fitting with such high but transient force that you don't need to hold the other part. The alternator has more than enough inertia.
Cheers Craig, I didn't know that!
I'm getting a whining noice from my alternator. Could it be from this?
Whining is probably inside the alternator, either get it rebuilt or replace.
@@CraigsDIY was told it might be the water pump but hey ho I'm no mechanic so will probably get ripped off anyway!
How to solve the entire disassembly of the gear block internal maintenance
Your issue was definitely cause you were turning the wrong tool lol. Turn the black spline tool counter clockwise the through tool is just to hold in place. This can literally be done by hand.
From what i know, you don't really need overrunning pulley if car have automatic transmission.
The main reason for the pulley has to do with the engine... modern gasoline & diesel engines can have multiple "ignition firings" (per cylinder) which cause multiple power pulses through the timing chain / belt and serpentine belt (per cylinder firing). Clutch pulleys help absorb these pulses because the alternator is able to continue to spin, rather than slow down & speed back up with those pulses. Power steering pumps, water pumps, AC compressors, don't have a heavy "rotating core" like the alternator... so there's no need for them needing a clutch pulley.
So the lesson if you dont know how things goes on or if you don't have right tools, do not start the job?
Air gun..eyze
Why are you working on the floor?
He is working on the floor because he is an amateur
Great tutorial video, you sound very English but donate in $ use lug nuts & wrenches🤔
We're all a bit Americanized sadly