Got the t-case shaft side u- joint in today and went smooth as silk. But, of course the rear axle side u- joint is very stiff only with the clips in. Uhhhg! I’m assuming the new-used driveshaft I got someone had bent the ears in at some point. Last ditch effort is to knock the ears back just a nats hair to get a freely moving u-joint. Just not sure how to do that...yet.

 

got the rear driveshaft rear u-joint to loosen up considerably. Still a bit of resistance, but nothing like before. Definitely not at smooth as the front portion u-joint. Pondering whether I should install.

 

What did you do then? Bang the ears out a little?

Not everybody will agree but if it were mine I would throw it in and send it down the road. Sounds like it's not too stiff. Check back in a couple days to see if it loosed up naturally. Only takes 5 minutes to drop it off the diff quick.

Also if you haven't already smacked the base of the ears around with a hammer after putting the joint in try that. It can help unbind the joints sometimes.

 

Ya I smacked it at the base of the ears and it was still really tight. I finally smacked it on the ears just a bit and then the base of the ears and it loosened up considerably. Still not as smooth as the t-case side.

 

It'll be fine after torque is applied to it by driving it. Personally, I wouldn't worry about it.

 

Thank you zingo and dave1123. I’m going to give it shot.

 

I put the new/used driveshaft in yesterday and install went well. Definitely an improvement, but still have that thumping noise under the seats when under load. I have new motor mounts and transmission mount and both check out good. I may toss on a t-case drop to see what happens since it only started doing this after the 3” lift.

 

It also may. Be a worn slip yoke. The thing to do is load up your slip yoke with anti-seize, it seriously helped with the knocking

 

What worked well for me is moly grease.

 

Thanks for responding Patman. On my 89 I read that the shaft is internally lubricated with the t-case fluid. My concern is will that anti-seize get into the t-case and maybe cause some problems?

dave1123 said the same about the slip yoke. I was hoping that’s not the problem, but it probably is.

 

It's supposed to be, but I found some axle grease helps anyway.

 

Thank you lawsoncl. I guess I may have nothing to loose at this point. Would axle grease be better than Copper anti-seize? Just thinking the anti- seize may stay in place for longer. My funds are very limited the remainder of the year or I would just fix it properly.

Im also considering trying a 1” t-case drop because it didn’t do this until the 3” lift. Temporary fix of course .

 

I just use some axle grease. I'd be hesitant to use antiseize.

 

I will give that a shot, thank you. I have red lithium grease, can I use that? Also do I just pack some into the inside of the driveshaft slip joint. Sorry for all the questions. This is unfamiliar ground for me.

 

Yeah, really only need a finger full smeared around the inside of the slipjoint. If you fill it up too much, it'll bottom out when it's compressed