Had the classic bad u-joints symptoms of shift clunking and vibration around 60mph. I put the new u-joints in, making sure the trans shaft was on the same side and position as before. Now my car vibrates noticeably at 50 and gets progressively worse. It gets pretty unbearable at 70. I'm not sure what could have gone wrong. Could both zerk fittings being on the same side be causing the vibration or maybe the u-joint didn't seat in the yoke right since I had the wheels on ramps instead of an unloaded suspension and the yoke not being able to spin? Not sure what to check. Thanks.

 

i doubt the fittings have anything to do with it. i'd get under it and take a look, maybe take it out and see if anything noticable is wrong. if i never seen anything i'd start over with new parts.

 

It's a bad sign, you need to take it out and check it. I had a very similar experience which left me stranded with a driveshaft lying on the ground. Real fun stuff at 70 MPH. Check the U-joints and see make sure the caps rotate freely. If there ok then check your drive shaft for discolored spots where a weight may have pop’d off.

 

Well I crawled under there and I realized that since I installed it with the yoke cups vertical, I didn't pay attention to the top and I falsely assumed the ujoint would center itself. One cap went past the edge a few millimeters and the other side was sunk in a few. So I held the caps on tight and centered the ujoint as best I could in the yoke while I tightened the retainers. Hopefully that does it. Both caps ended up being a few millimeters sunk in from the edge of the yoke. Will test it tomorrow. Seems strange that there's nothing built into the yoke to make sure the ujoint has to be centered before you can tighten it down. Thanks to all.

 

Whoa! Not good! You left out the clips that are supposed to center the U joints in the yoke. You are going to cause a major catastrophe! You should not have to CENTER THE U JOINT BY HAND! There is something built in that centers the U joint, but you left it out! They are internal clips that go in the grooves in the u joint caps.

 

No no, the clips that hold the ujoints to the driveshaft and tranny shaft are there. The other two caps on the differential side that go into the yoke must be manually centered into the yoke as far as I know now. The shop that pressed the old ujoints out for me and installed the new ones put all the clips in except for those 2 caps. Digging through other posts I found the same information as I just gave. They really wouldn't serve much of a purpose unless worst case scenario the yoke ujoint retaining clamps became only party loose and the caps started nudging out. But then you're in trouble anyway.

 

Again, No! The U joint caps that go into the differential yoke also need clips! You don't manually center a U joint. Please listen to me, I have done this correctly a lot of times. Look at a factory driveshaft that is correctly installed on someone else's car if you don't believe me. Somewhere along the line you lost the clips. The clips center the U joint. The straps don't locate it, they only retain the caps.

 

327 Maro is right. The clips have to be there to center the u-joint/driveshaft in the rear pinion yoke. Trust me on this. I'm chasing a vibration in the rear of my car and I've seen most of the drivetrain up close and personal. Nothing that rotates can be eyeballed and work right. It has to be mechanically held in place.

 

here i took a picture of the clips to see if it can help. (try to make the best of my car sitting in pieces)

 

I didn't lose them, we (he) just didn't put the last 2 on. One accidentally shot off when he was putting it all together and I wondered why he didn't seem worried. He said the last 2 were extra, I just didn't say anything since I figured they were only needed on the other 6 caps. It makes sense now. Hopefully I can buy 2 loose ones. For what it's worth though I eye balled it pretty good as far as vibrations go. Thanks all.

 

make sure you get those c-clips in!! I just did the same thing.. I have an 81 that i put a 700r4 into..Brought the driveshaft to get cut & balanced. installed driveshaft, but left out those clips by mistake..Took for a test drive, got about 4 miles from the house, and those two caps flew off while i was driving.. The car shook violently till i got it to stop.. Looked under the car, saw teh caps were missing and the driveshaft spun in the pinion yoke and wedged itself sideways.. U-joint straps were shredded and about to snap, pinion yoke needs to be replaced, driveshaft is most likely twisted, and the output shaft on the trans is shot. i can move it up/down and side to side by hand.. two .50cent clips cost me about a grand now.. this just happened last weekend..

get the clips