Ok hi everyone i just got my first car, 91 firebird v6 3.1L auto trans and was having a loud clunk when i slammed on it, so i figured it was the u joint and replaced those. Well when leaving my friends shop i had a vibration and still had the clunk. So i caused another problem (great). Well i fixed the clunk but still have the vibration. I know my front end is loose but it hadnt had a vibration before the new u joints so what could be the problem? Any ideas would help! Thanks in advanced Chris

 

If you don't get the U-Joints seated correctly when you install them, that will cause vibration and premature wear of the new u-joints and possible catastropic failure.

 

Did you put the clips on the xaps to center the joints in the yoke?

 

^^^ This

First thing to check: are both ends of the rear one sitting squarely in the yoke; not one end up on top of the little locating tab.

If it is, and then absolutely WILL NOT go down in there right, you have a needle that has come out, and is stuck between the end of the trunnion and the cap. In that case you probably already need to replace it, and make sure that doesn't happen again.

If all that is good, you probably bent one of the ears on some one of the yokes, taking the old OE plastic-retained ones out.

 

yank the shaft and move the joint lock to lock, if you feel ANY resistance this will cause runout. lightly but firmly tap the "neck" o the shaft on each side and then check the joint, this will seat the caps and if seating is all thay need this should correct your issue.

when replacing joints you can use the " tap the neck" method and it'll walk the caps right out of the shaft with no damage to the shaft, this is on steel shafts BTW.

another thing is the C clips may be just a tad too thick and you can grind a little off of the clip which will allow the cap to seat better.

to see if your ears are bent, measure the distance between the ears at the top and bottom. the distance should be 2 9/16 between the ears.

 

I have solved the problem. I over greased the u joint and now It wasn't allowing the caps to sit properly causing play in the driveshaft back and forth causing a vibrating noise but I took a cap off and took some grease out and now it is all fixed and I am all set to move onto cosmetic repairs now! Thanks for all the ideas!