Part number for S3 rear differential?

oyvind_norway

New Member
Joined
Sep 28, 2020
Messages
12
Reaction score
2
I went from D to L, you can keep the existing Haldex ECU to avoid having to programme the new one, it's just plug and play that way. What happened to your rear diff? Your oil disappeared like mine?
Yes, gone It is a mystery
 

HertS3

Registered User
Joined
Oct 17, 2018
Messages
1,185
Reaction score
374
Strengthens my case that the part is inherently flawed, how can Audi claim it's sealed for life if there are air vents on the top?? It's not a sealed system.
Audi dealer blamed the independent garage I went to of accidentally draining the rear diff oil when they changed the Haldex oil!! Ridiculous.
 

oyvind_norway

New Member
Joined
Sep 28, 2020
Messages
12
Reaction score
2
I use a independent garage to fix it for me because Audi just want to sell me a new part. They also tell me that the only part I can use is 0CQ 525 010S...
 

HertS3

Registered User
Joined
Oct 17, 2018
Messages
1,185
Reaction score
374
Yes, I had an independent fit a used one I got on eBay from a breaker, Audi will just want to sell you the newest version, not sure about the price in Norway but in the UK it was around £3,500
 

HertS3

Registered User
Joined
Oct 17, 2018
Messages
1,185
Reaction score
374
Wow I bought one from a breaker for £380!
 

alpesh26

Registered User
Joined
Mar 3, 2011
Messages
856
Reaction score
229
What are the symptoms of a knackered diff? Something on my car is whining at 70mph but only when im on the throttle, I can't place where its coming from.

I have replaced the oil in the diff due to accidently draining it (don't laugh) when doing the haldex oil so I know there is definitely oil in there as it took a full litre to fill it.
 

HertS3

Registered User
Joined
Oct 17, 2018
Messages
1,185
Reaction score
374
LOL kudos for doing stuff yourself anyway!

My made a whooshing sound which seemed to get worse on the motorway, plus if you floor it from standstill it sort of wobbles, not take off straight away. The whining appears to be bits of metal shaving going through the diff. When it went completely it sounded like I was dragging a tin can behind me
 

alpesh26

Registered User
Joined
Mar 3, 2011
Messages
856
Reaction score
229
LOL kudos for doing stuff yourself anyway!

My made a whooshing sound which seemed to get worse on the motorway, plus if you floor it from standstill it sort of wobbles, not take off straight away. The whining appears to be bits of metal shaving going through the diff. When it went completely it sounded like I was dragging a tin can behind me
I said don't laugh!! :wink:

Was it making noise regardless of being on the throttle? I might try closing the exhaust valves and see if that helps with my issue
 

HertS3

Registered User
Joined
Oct 17, 2018
Messages
1,185
Reaction score
374
I found that you could hear the noise best when off the throttle though presumably it made the noise all the time, don't laugh but I'd just put winter tyres on (first time I'd had some) and thought that the noise was coming from them!!
 

oyvind_norway

New Member
Joined
Sep 28, 2020
Messages
12
Reaction score
2
Mine has a rumbling sound from zero and all the way up to 80 km/h, and from 80 it sounds like Axel Rose on a very bad day
 

PrivateRy4n

New Member
Joined
Jan 29, 2021
Messages
5
Reaction score
1
My RS3 diff has gone and the part number from audi is ACR 525 010S but i have found a similar one 0CQ 525 010C, will this diff fit and be okay? what is the difference
 

jamal1

New Member
Joined
Nov 23, 2021
Messages
1
Reaction score
0
Mine has a rumbling sound that increases/decreases with speed, is it too far gone when this happens and needs to be replaced? Never had to deal with a problem like this before
 

HertS3

Registered User
Joined
Oct 17, 2018
Messages
1,185
Reaction score
374
Mine has a rumbling sound that increases/decreases with speed, is it too far gone when this happens and needs to be replaced? Never had to deal with a problem like this before
Could be, I'd get it checked out pronto
 

Wyseoldman

New Member
Joined
Mar 16, 2022
Messages
1
Reaction score
0
I'm the author of the above post - I know all about rear diffs! Mine is a late 2014 build (car delivered early 15) and I had the F variant on my car. You can get any 0CQ525010X where X is what you have or later; there were D, E, F, H, K, J, L and S I believe (S is the current version you get new from Audi if you fork out £3,800!!!)

There are a few knocking about on eBay, what I would say is play the waiting game, not many of these sell, if you watch the items or message sellers they'll give you big discounts on the prices they ask on their listing. If you look at the thread above, I found one guy that was willing to sell for around £200. I'd be weary of West Yorkshire-based dealers, the one I got was from a Nottingham breaker and (touch wood) all fine so fa

I'm the author of the above post - I know all about rear diffs! Mine is a late 2014 build (car delivered early 15) and I had the F variant on my car. You can get any 0CQ525010X where X is what you have or later; there were D, E, F, H, K, J, L and S I believe (S is the current version you get new from Audi if you fork out £3,800!!!)

There are a few knocking about on eBay, what I would say is play the waiting game, not many of these sell, if you watch the items or message sellers they'll give you big discounts on the prices they ask on their listing. If you look at the thread above, I found one guy that was willing to sell for around £200. I'd be weary of West Yorkshire-based dealers, the one I got was from a Nottingham breaker and (touch wood) all fine so far
Hi Hertz,
I am chasing a complete diff and Haldex for my Octavia, current part number is OCQ 525 010 D. I have found one from a 2020 T-roc same part number followed by AB, I am hoping this could fit??. Your thoughts would be very much appreciated.
Thanks.
 

HertS3

Registered User
Joined
Oct 17, 2018
Messages
1,185
Reaction score
374
Hi Hertz,
I am chasing a complete diff and Haldex for my Octavia, current part number is OCQ 525 010 D. I have found one from a 2020 T-roc same part number followed by AB, I am hoping this could fit??. Your thoughts would be very much appreciated.
Thanks.
No idea I'm afraid, I don't know what AB means
 
Top