80 quattro 2.6 rear diff mount ?

[R5T]

Evening guys

My rear diff is jumping about like a **** in a sock, every time I come off or on the throttle there is a half a second delay and the rear diff jolts up and smacks the underside of the car.

I swapped out the diff mount for another use one that I believed to be in better condition, for the first few days it was better but gradually went back to how it was before.

To save any confusion this is the mount in talking about :



Yesterday I filled the original one up with epoxy and fitted it, I'm getting vibrations like a solid mount but it's the same if not a bit worse in terms of the diff jumping up.

Is there any other mounts I can check/replace as audi want £120 for the one above.

Also .. It's becoming increasingly clonky changing gear (especially from first to second).

The car is a b4 80 saloon 2.6 Quattro, please note for the relevance of the thread that it is currently converted to RWD, the centre diff is welded.

Thanks

Sam


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[s2driveruk]

i'd check your cv joints for rotational wear, discovered my nearside rear was toast over the weekend, marked reduction in driveline shunt taking up drive and off throttle too following replacement

[R5T]

Can totally understand where your coming from, but I've actually witnessed the diff jumping, I jacked the car up on the back and drove it in gear, came up the the biting point etc .. Every time you hit the biting point the diff is moving a good 1-2 inches.

Sam


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[Sleeper_Avant]

the inner CVs wear and makes the diff jump

i sent you an Email Sam, please reply

[R5T]

Have replied Shaun, sorry once again !

What's the easiest way to upload a vid on here ? I'll show you exactly what it's doing.

How does the cv's wearing have an effect on the front of the diff ?

I don't really understand :/

Sam


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[Sleeper_Avant]

the balls on the Inner CV`s wear and they jump out of the holes they are seated in causing it to lock up and "jump"

unbolt 1 rear shaft at a time and with the diff locked see if it stops doing it

incidently,

i bet its the prop!! same scenario, same issue and if youve just been ****ing about with it chancing bits over it may well be that!!

[R5T]

Still can't locate anything, it's getting worse, and I'm sure there is something that is actually loose underneathe, even with the clutch dipped just rolling, if I hit a slight bump there is a metallic "cling cling" ..

How much rotational slam should there be in a half shaft ? And the prop ?

Sam


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[Mackers]

Diff backlash?

[andy10v]

There are two bushes (No. 6 in the diagram) at the back as well, also check the rear carrier is not cracked.

[R5T]

Right, just had ANOTHER look underneathe, if you lurch on the bit in point it is definitely the front of the diff that is moving, audi want £120 for the mount as it's the bracket aswell etc, has anyone got one lying around that is in good order that I could try ? Or is there a replacement for cheaper
?

Cheers

Sam


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[Sleeper_Avant]

A4 Quattro is the same

[Sleeper_Avant]

Pity your so damn far away or id come and have a look at it

[R5T]

Hmm .. I'll look into an a4 one ASAP ..

Here is a link to a vid of what it's doing :

http://youtu.be/3gaIwkSxoyg

Sam


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[Sleeper_Avant]

100% something mechanical has failed

the bush is doing its job perfectly!

[Sleeper_Avant]

with the engine off and car on axle stands,

try it in first gear (engine off obviously)

turn/rock the rear wheel left to right and have someone check to see where the slip/knock is coming from,

i bet its the prop to diff joint