Rear Differential

[Dalmatian]

Hi I’m after a rear differential to fit my Audi A4 B7 it’s a 6 speed manual Quattro1.8t, I’ve had a clunking for a couple of years and it’s getting worse so I need to find a replacement? Where do you recommend I look, I’ve tried eBay etc but there don’t seem to be any suitable ones around, is anyone breaking a similar car?

Thanks,

Nick

 

 

 

 

[Dan3222]

Hey Nick,

Are you 100% sure it’s the diff?  Have you looked for wear in the drive shafts ETC. Not common for a diff to give up the ghost these days unless they have run out of oil.

Have you been told it’s the diff?

[Dalmatian]

I’ve had it checked by my local independent, a local garage and a Mercedes specialist that I know, they all say it’s the differential. I know it’s rare, it only clunks when the car is warm and in 1st and 2nd gear but is getting worse, a new differential is £4300 from Audi.

Nick

[Magnet]

Hello Nick,

Sorry to hear of your problem. I too would follow Dan’s logic and question differential vs. prop. shaft etc. Issues, since the symptoms you suggest do not appear to be typical of diff. problems. 

OK, it has been checked, but my guess is that the differential is the suspect because they cannot find any other issue - not to say there isn’t - just to say they can’t find anything. 

Difficult one. 

Any vibration? 

Kind regards, 

Gareth. 

[Dalmatian]

No vibrations, it’s fine when the car is cold but when it gets warm or there are more people in the car there’s a thump/clunk when pulling away, this lasts a bit into second gear as well and then perfectly fine after that.

Nick

[Dan3222]

If I was you I would take it into Bristol transmissions ( there are two more listed in Bristol also). These guys work with all sorts of transmission systems. They could diagnose and give you a price on a rebuild if it is confirmed as diff. Might be a lot cheaper than £4K!!

i would be very interested if you followed up on here on the cause and fix though please. Every day is a school day for sure!! But my 50p bet is still not on the diff, but I am not willing to bet any higher! Lol

[Dalmatian]

I have taken it to Bristol Transmissions and they agreed it was the differential but said they couldn’t repair it, this is why I’m trying to find a used replacement.

Nick

[Dan3222]

Nick, that’s rubbish, that they can’t repair it. Did they say why? I am guessing there aren’t really spares for this diff as they don’t normally go. At least they have confirmed it’s the diff so any money spent will not now be wasted.

i would try 24/7part finder or another similar part finder, put in details and then an email is sent to all scrappies that are signed up. Hopefully you will get a better priced seconded hand unit.

if not here a couple of specialist Audi breakers to try

http://www.a8parts.co.uk/

http://vee-dubs.co.uk/

The following link is for a generic search as I mentioned, you might be lucky.

https://www.breakeryard.com/car-parts/audi

Best of luck. I guess I lost my 50p bet!!

[Dalmatian]

I think it was lack of spare parts that was the reason for not being able to repair it. Finding the correct differential is a nightmare, no one seems to know what they are talking about when I go to buy a used one, they quote the serial number as the 0ar******** number which is on the differential but this is only the differential case code, the important bit is HNQ (this is also stamped on the differential along with the date code) which gives you the internal gear ratio which is 4.1 in my case. No one seems to understand this even though I clearly state it when sourcing a used part. I had a differential sent from Germany, they confirmed everything was correct including the code but when it arrived it had HNR stamped on it which was incorrect so I had to send it back (the drive shaft flanges were 75mm dial instead of 70.7mm). 

Finding one for my configuration of car, 6 speed manual, Quattro, 1.8t seems to be a rare combination.

I will try the links above as cars come in to breakers all of the time but as I said they don’t understand what is required.

Thanks for all of your suggestions and feedback.

Nick

[Dan3222]

Your welcome Nick, sorry I couldn’t help more (my ego still bruised about my 50p bet though). I am really surprised it is the diff still. What a nightmare about sourcing one. Would have been so much better to have had yours rebuilt if possible but that’s not even an option. Best of luck getting a replacement, sure one will come up at some point.