Practical Diff Upgrade options for my B6

[kevinish]

Probably not a new topic, but the search wasn’t coming up with anything so here goes:

What practical options are there for fixing the incredibly annoying diff clunk? I love my ol’ B6, but if there is one thing i could change its the clunk when you need to change quickly from a lift to back on the gas. Reliability is key, as i drive this car all the time, including in lovely bay area traffic.

[CrickiKaze]

New bushing, either an assembly or the bushing alone but would need a way to press it out. I'm referring to after market though and would need to look for anything under 80 durometer. You could possible to OEM.

[Rerb]

I have this (or something similar) - It wasn't my diff. I did the ECS diff mount and center carrier bearing insert, and if anything the clunk got worse. Your clunk could be the diff, but mine seems to be coming from the trans/clutch area.

[QIKRNU]

Rerb do you still have an OEM Dual mass flywheel? If not, single mass flywheels have been known to occasion some trans noise.

[CrickiKaze]

Any other clunk might be the carrier bearing unless the shafts are worn, assuming hardware has been looked over.

[S4Bennett]

The clunk is probably the backlash on the ring and pinion too loose.

Need to find a shim or stackable shims to lash it tighter.

Oddly enough, I had two RS4 rear diffs end up with significant backlash. Both whine a little as well.

Haven’t had time to remove the existing shims, measure diameter and thickness, and have a variety of thicknesses machined or maybe I can find an OTS equivalent.

[Rerb]

The clunk is probably the backlash on the ring and pinion too loose.

Need to find a shim or stackable shims to lash it tighter.

Oddly enough, I had two RS4 rear diffs end up with significant backlash. Both whine a little as well.

Haven’t had time to remove the existing shims, measure diameter and thickness, and have a variety of thicknesses machined or maybe I can find an OTS equivalent.

This makes sense, I still have the dual mass flywheel and significant diff whine between 40 - 50 and 90 - 100. How do you measure backlash?