FC driveshaft U-joints tend to go bad and cause vibration problems, and this happens rather early in the car's life in my opinion. I was wondering if FDs have this same problem. I have a driveshaft that has about 125k on it, and I'm wondering if I should install it or if I should expect that it is already bad or will fail soon.

 

The FD driveshaft doesn't typically have issues as long the driveline is aligned properly. That's what will wear on the joint causing the need for replacement.

 

I've been through 3 fc driveshafts in the last 4 years due to those damn front diff mounts always breaking!

I don't see the FD having such an issues as long as the PPF is aligned.