I presume you are referring to the ring gear carrier when you say cardan. If the bearings are shot, they can be replaced, but the guy doing the work has got to know how to set up a rear end after replacing the bearings. Make sure you've got the right tech before you start this adventure...Good Luck.. BTW, you can't repair a rear end by adding thicker lubricant.
1987 BMW 325
[This message has been edited by jeffsr (edited 06-04-2000).]