Auto gearbox oil change - a8 quattro d2

Doug773 · #1 29th February 2012, 12:19 AM

Hi there!

My car is a 1996 A8 D2 4.2 QUATTRO, 94K.
My mechanic told me it would be a good idea to change the transmission oil.

The Audi dearlership in London was not able to sell me the right kit for that because they could not figure out which transmission my car uses: CML or CMN, by the chassis number I provided them.
My question is: do you guys think that it's really necessary to do that? Will it do any good for the transmission life? I never had any issue with it (knock on the wood 3 times...).
I've checked all my car documentation and couldn't find anything about that transmission codes.
Any help will be very welcome.

Doug

Singh · #2 29th February 2012, 02:13 AM

As your car is a 96, it will more then likely have the four speed box, which is said to be stronger then the fifth speed. Some people think its a good idea to change the fluid, others say if it hasn't been done regularly and you change it for the first time in x amount of years you could end up doing more damage then good, I would leave it as is, especially if it is a four speed.

Follow this guide for part numbers and DIY instructions, welcome to the forum.

http://www.audipages.com/Tech_Articl...servicing.html

Doug773 · #3 29th February 2012, 03:08 AM

Thank you so much!

Yes, mine is a faithfull 4 speed box, I've been keeping it for 10 years! No big issues so far, drive just right. But from some 4 years back, running idle it sounds like a diesel engine, no more that nice V8 muted purr. Asked some 4 different technicians to check it, they spent several hours checking every pulley etc and found nothing!
Maybe some valve clattering, I don't know. Otherwise the car run just great. It sounds OK at any rpm above idle.
Have you ever heard something like this before?

Many thanks! BTW, nice MJ pic, one of my fav artists!

Cheers,

Doug

Architex_mA8tey · #4 29th February 2012, 04:56 AM

Welcome from me too

Your gearbox code should be on your build sticker both on the car (in the spare wheel well) and on the front inside cover of your original service booklet if you have it.

The gearbox code position is shown on this thread HERE

notorious · #5 29th February 2012, 05:51 AM

>> running idle it sounds like a diesel engine

Camshaft chain tension is maintained by oil pressure in our engines AFAIK.

If oil pressure is not that strong enough at idling, then chain starts to rattle. When RPM goes above idle, the oil pressure becomes strong enough to tension chain properly. Change oil pump and problem should disappear.

sloss · #6 29th February 2012, 06:09 AM

Quote:

Originally Posted by notorious

>> running idle it sounds like a diesel engine

Camshaft chain tension is maintained by oil pressure in our engines AFAIK.

If oil pressure is not that strong enough at idling, then chain starts to rattle. When RPM goes above idle, the oil pressure becomes strong enough to tension chain properly. Change oil pump and problem should disappear.

But it's a petrol engine so will be cambelt - yes?

mannyo · #7 29th February 2012, 06:20 AM

Each bank of cylinders is driven by 2 camshafts (V8 has 4 camshafts) , the first camshaft is driven by the cambelt whereas the second camshaft is driven by a chain that connects both camshafts together inside the head.

Dezzy · #8 29th February 2012, 07:08 AM

I'm guessing it's CML, it's also on the box it's self but you'll have to get it on a ramp or similar to see.

I had my box done recently, fluid and filter. No issues...... Yet!

notorious · #9 29th February 2012, 07:14 AM

Right. These two chains are located on the back side of the engine. So if engine sounds diesel when idling the first thing is to chech the sound of back top side of cylinder head, not the front side where all pulles and belts are.

If these are chains, than it's almost 100% low oil pressure at idling. Warning lamp still doesn't come on, but it is enough to hear the rattling sound. Can be further diagnosed by measuring oil pressure at idling by connecting manometer.

Subframe out, engine sump out, and check if oil pump is clogged with debris. If not, then change oil pump (plug and play operation).

ainarssems · #10 29th February 2012, 01:35 PM

Quote:

Camshaft chain tension is maintained by oil pressure in our engines AFAIK.

If oil pressure is not that strong enough at idling, then chain starts to rattle. When RPM goes above idle, the oil pressure becomes strong enough to tension chain properly. Change oil pump and problem should disappear.

His is 96 32V, no chain tensioners on 32V