Hey jeepers. I had a bad u joint on the front of my front drive shaft (pinion side). I replaced the u joint but it was extremely stiff after I installed it. I tried a few taps on the shaft with a hammer and it loosened up a bit but it's still quite stiff. When I installed the shaft back in I get a thunk from the drive shaft when in 4wd. Mainly when I'm accelerating. I removed the shaft and ran it in 4wd and no noise and the noise wasn't there before replacing the joint. My question is would the u joint being stiff cause this noise and if so how do I fix it?

 

Was it difficult to get the lockrings in? Sometimes you can collapse the driveshaft ears together enough to bind the joint or make it impossible to get the lockrings in. You have to take it apart and spread the ears a little. A good sized hammer works well.