I have a 1999 Audi A4 Quattro, 2.8L. I have been hearing a rattling noise, while driving, whenever the car drives over bumps, holes, rough pavement and any other irregular ground. I thought it was a motor mount, however, I took the driver's side wheel off and discovered that there is leaking coming from the axle. It has sprayed the grease all over the wheel well and all over the shocks and as well. I can see where the leaking is coming from and it is on the axle shaft where the shaft meets the rubber boot on the wheel end of the axle.

My question is, is there a way to repair this leak or should I buy a new axle? Can I just replace part of the axle or should I buy an entirely new axle? Also, could the problem possibly be the CV joint, and if so, can I replace just the CV joint or do I have to replace the whole axle?

 

Yes they cv joints themselves can be repaired but i looked em some prices and it doesn't show to be all that worth it. Usually you can tell when your cv joint is bad by turning your wheel all the way to the left or right and accelerating, if its shot it will make a clicking sound more than a rattle. go test this out and see if it happens here are some prices, they may not be the cheapest around but just to give you an idea

http://www.ecstuning.com/Audi-B5_A4-...in/Driveshaft/

 

http://www.youtube.com/watch?v=kooqLH8EmYQ

Made this a while back

 

my cv boot was torn so i was about to replace my driver side axle but the replacement i got was a little longer (by an inch) so we end up just replacing the cv boot from another axle. it would be a lot easier to replace the axle itself rather than just the cv boot/joint. btw my axle is fine, just the cv boot was the problem.

 

If you're leaking axle grease, and you don't know for how long, assume that your joint is getting accelerated wear. FCP Groton sells CV rebuilds for $61 per joint. Replacing only the boot may do it if you just started losing grease, but if it's beengoing on awhile, whether or not you know it, you're prolonging the inevitable CV joint failure. I'd just rebuild the joint and be done with it.