forum.audiv8.com Foren English Audi V8 Forum Rear torsen issue?

I've noticed when the car is cold, and occasionally after being driven for a short while, that turns at junctions and very tight turns at low speed, especially right turns, the car has started to resist the turn. If the surface is loose, then the inside rear wheel will skip. The diff is obviously locking up a bit.
Obviously, I'm going to check fluid level, but there's no sign of any leak.

Is there something to be particularly concerned about?

I'm guessing the Anti Lock System might be the cause.

Or the Anti-Blocking-System?

Perhaps one of the ABS-Sensors? Any fault about that in the ECU?

ok. thats interesting. Anti-lock = ABS?

I didn't think there was any direct interaction between the two. However, i've noticed a slight response from the ABS when braking at very low speed- parking.

how would ABS affect diff?

Normally not, the diff is a pure mechanical komponent, but the ABS takes some effects that it fells like a diff problem...

It would be just a ABS-Problem... ckeck transmission-ecu about this...

if the ABS register different wheelspeed, in some case the hydraulic clutch (middle diff) in the transmissionbox will lock and it feels like a damaged/blocked rear diff...

OK. That's curious, but worth looking at. It certainly feels like the rear diff has wound up. Like on the ur-quattro, when the rear diff is locked.

However, I hadn't even considered that the ABS ECU had any direct input to the transmission ECU. ya learn something new everyday.

Cheers

There MUST be a direct connection, then how else the transmission-ECU knows when it should lock the middle-diff? it have no other input than from the ABS-sensors (wheelspeedsensors)....

Roy already explained the coherences between ABS and transmission ECU.

Especially if there is no automatically disengagement or flashing warning lamp of the ABS, check the sensor rings at the rear outer drive shaft joints. Possibly one is loose or cracked.

Read out ECU. Recorded faults, meaning implausible wheel speeds also point to a sensor ring problem. Another option are rusty speed sensor plugs. Defective wheel speed sensors should appear as defined malfunction.