Worn rear diff

[dan_b]

My rear diff is thunking quite a lot these days when you drop the clutch in fairly casually, I'm guessing the rear diff is starting to get a bit jaded - I recently replaced a few mounts and bushes, so I'm sure it's the diff.

What's the damage for a replacement one of these? Anyone got any sources of re-conned ones? I seem to remember Jamo had a nightmare getting his replaced recently?

I'm lining up a fair bit of work for the S2 for Christmas, treating the dear old thing

[Mikes2]

Could be the centre propshaft bearing or play in the cv joints at either end. I'd be surprised if the diff is worn unless it's low on oil

[dan_b]

Most of the play in the transmission seemed to be coming from the rear diff itself - we had it up on the lift and dropped the clutch in and out - you could see it moving quite alot when you brought in the clutch - although I guess you'd expect some slack of course? I did think it might also be propshaft bearing as well, but I guess you've got to start somewhere?

Is there a service schedule for changing gearbox/ diff oil?

[Fat Audi 80]

no doubt according to Audi they are "sealed for life"

But I am sure someone on here will come up with a better answer!

Cheers.

Steve

[pastures16]

i was thinking the same what oil do we use for the gearbox and diff

[caterpillar]

if the bearings are worned out,the clearens between the cron and pinion are too BIG.change the bearings.are not so bad price for them .cron and pinjon are the same in ALL audi(4,11-1) same partnr and so on. if some one need, i have the partnr on the pc.....

[4WheelDrifter]

GL-4 or equivalent in the gearbox.
GL-5 or equivalent in the rear diff.

[s2driveruk]

I think the diff oil is SAE75/90 can anyone confirm? Dan have you changed the gearbox mounts? they minimised the slack in my drivetrain for a good while thought eh thunks are slowly coming back, i think mine is the centre bearing on the prop, about the only thing i've never replaced...

[dan_b]

Yeah I've done the gearbox mounts and all the rear diff mounts (although I've still got that accursed Powerflex Bush in there on the rear diff which still gives me enough low-rpm transmission vibration to make my cds skip at about 1600rpm!). The centre bearing on the prop looks ok according to the mechanic who looked at it this morning - although I'm sure it's not as good as it was when new!

[Jas11n]

Gearbox;

SAE 75w90 (VAG ref; G052 911A)
GCR 6-speed = 2.7 litres (RS2 = 2.3 litres) (5-speed = 2.85 litres)

Rear Diff;

GL 5 SAE 90 (VAG ref; MIL-L2105B)
1.3 litres.

From my VAG gearbox manual.

HTH's

Jas

[dan_b]

Ok, if I change the rear diff, what parts do I need, and what else should I change while it's up on the ramp with its guts hanging out?
What's the part number for the standard OE rear diff mount that goes on that big bracket (I want to remove the poly bush I've got as it transmits too much vibration back in to the chassis)?

[Billman]

I have read in a german forum that the Castrol TAF-X is allmost th ebest for the gearbox and the SAF-XJ for the Diff! Can someone confirm it? Anyone using them?