front diff problem

[Wiell]

find something wrong?


that is my second one going kabom.
Anyone having any thoughts on why? it was during a launch.

[Jonnybravo]

Are you loading the transmission up before you launch it ?

[Wiell]

yes. i have broken two diffs now. this one was when i Launched it, but the other one was when put in second gear.
Many dont seem to break the diff but the gearbox instead.
the engine put out about 460bhp.

[Jonnybravo]

Have you or anyone else tried Redline Heavy Shock Gear Oil ? Seems to do the trick for a lot of other people but I have no idea if its suitable in the Audi boxes.

Not saying its the answers to your problems but it is seriously good

[Error404]

are you changing the crown wheel with the replacement diffs?

[Wiell]

jonnybravo, iam using redline heavyweight shockproof gearoil. thinks thats why the gearbox is holding but not the diff sadly.
want to get a hold on a 6speed s2 gear linkage so i can put a 01e gearbox in.

error404, no iam not. should i?

[Error404]

Yes the crown wheel is matched to the output shaft of the gearbox.
You must chnage them both together. Or when you fit a new diff you must resue the original crown wheel

[Wiell]

crap, that wheel is long gone. that was on the first diff i broke. this last diff i have driven 5000km with. so it cant be so off.

[Error404]

if it is overheating the diff oil it will not do you any favours, it won't protect the gearbox... like if you use too thin oil in your engine. I would scrap the gearbox and fit a different one.

[speeding-g60]

the ring gear (crown?) and the pinion are matched sets. they have numbers that are engraved into the side of them so they stay together.

[Wiell]

well that crown wheel has gone to quattro heaven. if it breaks it breaks.

[Audi Parts Guru]

the ring gear (crown?) and the pinion are matched sets. they have numbers that are engraved into the side of them so they stay together.

And they MUST be set up correctly in terms of the diff pre load and meshing of the teeth

[Wiell]

diff preload?

[speeding-g60]

backlash.....

http://www.drivetrain.com/parts_catalog/ring_and_pinions/ring_and_pinion_installation_instructions.html

[Error404]

The pre-load dimension determines the axial force exerted on the diff bearings when installed in the casing - it should be -0.25mm IIRC