I have a 94 a4 car (3.23) and have opportunity to buy a 96 m6 rear (3.42) is this a direct swap ? or what will need to be changed other than having the computer reset for the speedo. My 94 does not have traction control or abs and I dont know how the 96 rear is set up with a manual trans.

 

The axles are a direct swap. Since you don't have abs it doesn't matter if the 96 is traction control or not. If it is traction control you may have to use the brake hard lines from your 94 axle. If you ever want your abs to work you need a non traction control rear. I swapped a 3.42 axle into my 2.73 car and had to change the transmission shift points in addition to correcting the speedometer. I don't think changing the shift points would be necessary with such a small change in ratios.

Even though you didn't ask, unless something is wrong with your 94 axle or you're getting the 96 axle very cheap, I don't think the slight change in ratios is worth it.

 

The 3.23 I currently have is making some unusual noises while turning that seem to be tied to wheel speed, I have checked the u-joints and raised the rear axle off the ground and spun it and no noise. I am getting the whole setup for $150 so I figured it would be worth it and possibly fix my problem at the same time.

 

Sometimes noises when turning just mean you need some GM limited slip additive.

 

I put in Lucas synthetic 85/140. It still makes noise and seems to be getting worse.

 

Factory recommendation is GL5 80W90 with 4oz . of GM limited slip additive.

 

You didn't add any LSA.

 

I realize that the manual calls for 80-90 with L.S.A. I went with the heavier Lucas fluid to see if the noise went away, Lucas claims no L.S.A. is required with their fluids.

 

Yeah and other brands say their LSA works just as well as the GM stuff, when it doesn't. The posi can make some really terrible sounding noises when it does not have the right stuff in there.