1998 A4 2.8Q Triptronic - Rear Differential
 

My uncle was going to give away his '98 A4 2.8Q w/ Triptronic, but instead he's going to give it to me for a song. :) The only catch that I can see is that there's noise coming from the rear differential. The frequency of the sound increases with road speed, so I'm guessing it could either be the pinion bearing or the actual ring and pinion gears. It sounds like a gear noise, but a local transmission shop tells me that it could still be the bearing. I'm pretty handy, but have never tried to repair anything like this. Is it worth trying to repair, or would I be better off just replacing the unit? If replacement is the way to go, what years interchange for the rear differential carrier? I found one on ebay from a '99 2.8 with the manual transmission for about $125 +shipping, and it only has 64K on it. Any suggestions?

TIA!

RE: 1998 A4 2.8Q Triptronic - Rear Differential
 

it could just be your wheel bearing. lift up the back of the car and jiggle the wheels. if theres play its only the wheel bearing, an easy fix. and if it is the rear diff, you can get a LSD then.

RE: 1998 A4 2.8Q Triptronic - Rear Differential
 

How tough is it to replace the wheel bearings? Are they tough to come by? As far as the LSD goes, how much would that run me? I'm brand new to the Audi scene, so I dont' have much of a reference point for this kind of stuff.

Thx!

RE: 1998 A4 2.8Q Triptronic - Rear Differential
 

i got an upgraded german wheel bearing from blauparts for $60 and had it installed for $140. when the other side went i just took off hte upright, just take off the bolts some may be rusted, and took the upright to a shop with a press and got it donr $20 plus 60 for another bearing. LSD is completely optional and costs about $400. or you can go to a slavage ard or ebay and get a used rear diff and put it in about 2 hours.

RE: 1998 A4 2.8Q Triptronic - Rear Differential
 

Any idea if a diff from a '99 with a manual transmission would work with my setup?

RE: 1998 A4 2.8Q Triptronic - Rear Differential
 

Correction to abovepost - the one I found on ebay is from an '01.