S3 whine from Haldex/Rear Diff

[rustysheriff360]

In the last couple of weeks, my S3 has developed a whine which sounds very much like a worn wheel bearing. The whine starts quietly around 30mph and gets louder from that point onwards.

I took it to my local independent who came out with me for a test drive and afterwards, put it on a ramp. To try to find the source of the noise, he checked around various places like the wheel bearings, gearbox and propshaft with a stethoscope. The wheel bearings were apparently almost silent but the Haldex/Rear diff made a noise.

Since seeing the Indy, I also went to a local gearbox specialist (recommended by the Indy) who also came out for a test drive but like the Indy, he wasn't sure of the source of the whining. He was quite happy to have my car for a few days so that they could get the Haldex unit out for further inspection.

I have also spoken with the Indy who has looked through the Audi workshop manuals only to find that there is no mention of repairing this unit. I have also spoken to Audi who don't sell any parts for this unit but would be happy to sell me a new one £2400 .
My problem now is that I'm not sure if that's the source of the problem and wandered if others have had work done on this particular part. I have searched and found a few old posts where owners have had a whining noise and had the Haldex unit replaced under warranty and that has fixed the problem.

So, has anybody had work done to this unit? If yes, were parts easy to source such as bearings, seals, etc as my local gearbox specialist said he's not done one before and is not sure if he will be able to get parts for it?

Does anybody have a better way of testing it? I've been told that trying to run the engine to drive the wheels when they are off the ground causes problems with the traction control.

One of my friends has said that they have a piece of monitoring equipment in his garage which consists of a number of sensors that can be placed on various points on the car and allows the user to be listen for noises while the car is driven. This is probably my next option. Anybody used this and found it to be useful?

Any advice would be welcome and thanks in advance for any information.

 

[MalcB]

Unfortunately it seems to be quite common. I've just been through this trauma. More likely the diff than the Haldex unit.
Apparently the noise is caused when the teeth on the crown wheel and pinion start to break down. Mine went at 90K miles.
Have a read.
http://www.audi-sport.net/xf/threads/weird-noise-from-the-back-end.268016/

You can pick up second hand ones but check the part numbers !! Tom Walker at Retro Resus sorted mine. Top bloke.

 

[rustysheriff360]

Thanks for the info MalcB.

Mine is definitely a whine/drone and not a grinding/rubbing noise, as the info in the thread suggests. Based on investigations so far, it does point to the diff.

 

[mstancicmaximal]

In the last couple of weeks, my S3 has developed a whine which sounds very much like a worn wheel bearing. The whine starts quietly around 30mph and gets louder from that point onwards.

I took it to my local independent who came out with me for a test drive and afterwards, put it on a ramp. To try to find the source of the noise, he checked around various places like the wheel bearings, gearbox and propshaft with a stethoscope. The wheel bearings were apparently almost silent but the Haldex/Rear diff made a noise.

Since seeing the Indy, I also went to a local gearbox specialist (recommended by the Indy) who also came out for a test drive but like the Indy, he wasn't sure of the source of the whining. He was quite happy to have my car for a few days so that they could get the Haldex unit out for further inspection.

I have also spoken with the Indy who has looked through the Audi workshop manuals only to find that there is no mention of repairing this unit. I have also spoken to Audi who don't sell any parts for this unit but would be happy to sell me a new one £2400 .
My problem now is that I'm not sure if that's the source of the problem and wandered if others have had work done on this particular part. I have searched and found a few old posts where owners have had a whining noise and had the Haldex unit replaced under warranty and that has fixed the problem.

So, has anybody had work done to this unit? If yes, were parts easy to source such as bearings, seals, etc as my local gearbox specialist said he's not done one before and is not sure if he will be able to get parts for it?

Does anybody have a better way of testing it? I've been told that trying to run the engine to drive the wheels when they are off the ground causes problems with the traction control.

One of my friends has said that they have a piece of monitoring equipment in his garage which consists of a number of sensors that can be placed on various points on the car and allows the user to be listen for noises while the car is driven. This is probably my next option. Anybody used this and found it to be useful?

Any advice would be welcome and thanks in advance for any information.

Hi man, I had the absolutely same problem on my A3 quattro. Strange noise was comming somewhere from under the back seat (From my opinion it was louder on the right side). First thing that come to my mind is to change rear right wheel bearing, and I was sure that will be the solution. But of course, that wasnt the problem, noise was still there. After doing some research and going from garage to garage I’ve finally solved that problem. There is one bearing in differential which costs somewhere around 30euros, and mechanic took 70euros for demontage diff - change diff bearing and change oil in differential - packing whole diff box on car again, so whole problem was around 100euros. Just to know if u go to the dealer they will bring you solutions for 1000+ euros and even more.. I will post you a pics of exact bearing that you need, it is the same for a3/s3 and rs3 diff boxes, all you need to do is to write down the numbers from bearing (you can see them on pics) and to buy it in any spare part shop. Stay tuned guys.

 

[Daveyonthemove]

I think the OP probably sorted this, or moved on the car as he posted his problem 4 years ago.

 

[mstancicmaximal]

I think the OP probably sorted this, or moved on the car as he posted his problem 4 years ago.

Yap, sure he is. But maybe someone else will stuck with the same problem and may find this reply useful.

 

[paddy]

I think also it depends on what version of the dif you have. You seem to be in a 8v ? I sent my diff of to a specialist and he said its just not designed to come apart, too much of it is riveted and pressed together.

 

[mstancicmaximal]

I think also it depends on what version of the dif you have. You seem to be in a 8v ? I sent my diff of to a specialist and he said its just not designed to come apart, too much of it is riveted and pressed together.

They said that to me too, and that it is a closed system not meant to be opened etc.. And there were nothing for me to lose in that case. I’ve found used diff box from a test vehicle in Germany, told my brother (he lives in Germany) that I need to buy that but also told him to wait with a call day or two so I can open that diff box at garage where my friend works. And I said to you what was the problem, box is opened, flushed, bearing replaced, oil replaced too, closed and that strange noise disapeared. So I didnt have to buy whole new diff box, and it was a very very cheap solution. Ya it is A3 8V model, but diff boxes changes from model to model but with a minor improvements, you can get that info if u call your dealer and give them VIN of your vehicle, they say to you OEM of any part that is placed in your car by default in the year when is fabricated. But from year to year there were minor improvements (or not, maybe that is just a policy of dealers) and you will hear that there is compatibility (I’m saying for my paticural experience for diff boxes) between models fabricated years 2014,2015,2016,2017 etc.. OEM numbers were different just in last symbol (example oem number .d, oem number.s, oem number .e etc) these letters after dot says about version of diff boxes (that is their story, but that can be true, and from the other side that can be the literally the same box just indexed different so they can sell you for more money because your car is a few years younger etc).. But it is what it is, there is a major chance to solve that problem very very cheap (if you were not driving for 20000-30000km with that noise and maybe caused more damage to the inside of a case where bearing is placed). My advice is if you hear any noise comming from the back diff, asap find a guy and simply tell him what needs to be done, pay him, and you will solve that easy.

 

[mstancicmaximal]

I think also it depends on what version of the dif you have. You seem to be in a 8v ? I sent my diff of to a specialist and he said its just not designed to come apart, too much of it is riveted and pressed together.

Specialist said that diff boxes werent meant to be open. Ofc thay will say that, but man, these pics that I’ve posted above, that bearing is from the inside of the diff box, that is not photo of the buyed spare part, that is damaged bearing from the inside (you may not be able to see that damage from these pics)..

 

[Daveyonthemove]

Does anyone on here change the diff fluids, and if so at what interval?

When I bought mine 2 years ago I changed every filter and fluid on the car including Diff oils. I did have a transfer box fail and sourced a used one to replace it, but my Diff's have been fine (touch wood) with 135k miles on them.
I might be 'old school' in my thinking that spending a small amount of money on a fluid change is more appealing than spending large amounts of money replacing the part further down the road.

 

[mstancicmaximal]

Does anyone on here change the diff fluids, and if so at what interval?

When I bought mine 2 years ago I changed every filter and fluid on the car including Diff oils. I did have a transfer box fail and sourced a used one to replace it, but my Diff's have been fine (touch wood) with 135k miles on them.
I might be 'old school' in my thinking that spending a small amount of money on a fluid change is more appealing than spending large amounts of money replacing the part further down the road.

Honestly I think that I woudnt change oil in differential because I dont believe that it will come to my mind if u understand me. But with this problem I had not so long ago, there is a checking valve on diff box so you can see quality of the fluid which is inside of a diff box, a good mechanic must to know more about quality of inner fluid so he needs to suggest fluid change if that is necessary. But again, if u ask me, that isn’t too expensive so why woudnt you change that fluid, it can’t do nothing bad to your diff, on the contrary it can be just better, that is my opinion. When we are talking about changing fluids, I strongly advise you to change whole fluid in coolant system, even before every winter, otherwise (models such a3/s3/rs3, vw6/vw7 and im sure there is more models in vag) you have serious risk of loosing heating inside cabin, which leads to changing the heating matrih which means demontaging half of the interior dashboard for this heater mateix to be changed, and that is a very very stresful and complicated job to do (off the topic but may find useful )

 

[Daveyonthemove]

I'll be changing the coolant in mine soon anyway because I have a Thermostat that is stuck open, so when the lock down is lifted I will be replacing it and the coolant and serpentine belt will be done at the same time.

 

[kevingriffith]

Hi man, I had the absolutely same problem on my A3 quattro. Strange noise was comming somewhere from under the back seat (From my opinion it was louder on the right side). First thing that come to my mind is to change rear right wheel bearing, and I was sure that will be the solution. But of course, that wasnt the problem, noise was still there. After doing some research and going from garage to garage I’ve finally solved that problem. There is one bearing in differential which costs somewhere around 30euros, and mechanic took 70euros for demontage diff - change diff bearing and change oil in differential - packing whole diff box on car again, so whole problem was around 100euros. Just to know if u go to the dealer they will bring you solutions for 1000+ euros and even more.. I will post you a pics of exact bearing that you need, it is the same for a3/s3 and rs3 diff boxes, all you need to do is to write down the numbers from bearing (you can see them on pics) and to buy it in any spare part shop. Stay tuned guys.

What year is/was your S3? I'm having this problem with my 2014 Audi S3 (noisy rear diff) which I believe is either just a common fault or poor maintenance from previous owners. I think I've come to the conclusion that it's the tapered roller bearing inside the rear diff unit which needs to be replaced but I'm not having much luck finding a replacement part that fits my car. Planning to buy a second hand rear diff and fit it for the meantime and replace the bearings in my current one so at least there'll be a back up if things don't go to plan!

 

[Hobo_Joe]

What year is/was your S3? I'm having this problem with my 2014 Audi S3 (noisy rear diff) which I believe is either just a common fault or poor maintenance from previous owners. I think I've come to the conclusion that it's the tapered roller bearing inside the rear diff unit which needs to be replaced but I'm not having much luck finding a replacement part that fits my car. Planning to buy a second hand rear diff and fit it for the meantime and replace the bearings in my current one so at least there'll be a back up if things don't go to plan!

I had this whine on my facelift 8P S3 a few years ago... I foolishly ignored it thinking it was a wheel bearing noise. One day while taking off from a stop, I hear a loud bang and subsequent grinding (which turned out to be my rear diff going pop).

If you let it go this far, then it leads to catastrophic failure (my crown and pinion gears sheared their teeth). They are also impossible to rebuild as the gears are not sold separately and the crown gear is welded to the shaft. I bought a second hand one, but the gearbox specialist I took my vehicle to said that they could replace the bearings which cause play in the shafts (the whining sound). Maybe if you can find a workshop who can do this for you, it will be cheaper than sourcing an entire diff!

Here is a video I found of a bearing replacement done by a garage in Australia: Rear diff/Haldex bearing replacement

 

[vajdans]

Hi man, I had the absolutely same problem on my A3 quattro. Strange noise was comming somewhere from under the back seat (From my opinion it was louder on the right side). First thing that come to my mind is to change rear right wheel bearing, and I was sure that will be the solution. But of course, that wasnt the problem, noise was still there. After doing some research and going from garage to garage I’ve finally solved that problem. There is one bearing in differential which costs somewhere around 30euros, and mechanic took 70euros for demontage diff - change diff bearing and change oil in differential - packing whole diff box on car again, so whole problem was around 100euros. Just to know if u go to the dealer they will bring you solutions for 1000+ euros and even more.. I will post you a pics of exact bearing that you need, it is the same for a3/s3 and rs3 diff boxes, all you need to do is to write down the numbers from bearing (you can see them on pics) and to buy it in any spare part shop. Stay tuned guys.

Hi. Sorry for resurrecting this post once again. Could you pm me? I have the same problem with my diff, and seeing we're from the same region would like your mechanic recommendation.

 

[tayyar]

Hi guys, I have a same propblem ( rear differential whinning noise), I was hoping it is no differential, I changed to wheel bearings, rotors etc, haldex fluid and diff. fluid, noise not gone, I went to my friends shop and we lifted up to car and searched to detailed. differential making noise , I will try to change to bearıngs but mechanics guys affraid to dismantle it, and also Audi authorized service not carryıng out your problem, they want to change completely the part.

mstancicmaximal how is going the process? did they remowed completely rear diff. from the car ? and could you share the parts (seals and o-rıng part numbers? how many hour does it take?​

and also I found used ( almost new) rear diff. but its removed from 2020 s3 and its code is 0CQ525010P, But mine is 0CQ525015B, will it be fit ? I'm thinking to buy it after collecting detailed information. best one is to remove the my noısy diff. but our guys are afraiding to remove it.
Audi guys, please write me also from whatsapp, I will very glad to see your messages.
Thanks.
my phone : +905375615802

 

[tayyar]

Hi guys, I have a same propblem ( rear differential whinning noise), I was hoping it is no differential, I changed to wheel bearings, rotors etc, haldex fluid and diff. fluid, noise not gone, I went to my friends shop and we lifted up to car and searched to detailed. differential making noise , I will try to change to bearıngs but mechanics guys affraid to dismantle it, and also Audi authorized service not carryıng out your problem, they want to change completely the part.

mstancicmaximal how is going the process? did they remowed completely rear diff. from the car ? and could you share the parts (seals and o-rıng part numbers? how many hour does it take?​

and also I found used ( almost new) rear diff. but its removed from 2020 s3 and its code is 0CQ525010P, But mine is 0CQ525015B, will it be fit ? I'm thinking to buy it after collecting detailed information. best one is to remove the my noısy diff. but our guys are afraiding to remove it.
Audi guys, please write me also from whatsapp, I will very glad to see your messages.
Thanks.
my phone : +905375615802

sorry guys, my diff. code is 0CQ525010K not 0CQ525015B.

 

[tayyar]

Hi one side is LM503349/LM503310, other side : LM806649/LM806610.
Oil seals : 2 pcs corteco 01033862B, there is the seal sizes if you want to other brand :67X83X8.