Still vibrating, and I am pretty sure i have it down to maybe 4 ft lbs. Could i have ruined the u-joint by having it overtightend (maybe 15-20 ft lbs) for 30-40 miles of driving? The first time I felt the vibration, I loosened the nuts up and the vibration went away. Then I put on new straps and nuts, used a torque wrench to tighten to 8 ftlbs, but it was on a 1/2" torque wrench using an extension with a u-joint in it to let me get at the nut, and it was at a very odd angle to clear the differential. So, possibly, it was tighter than 8. But when I drove it it vibrated pretty bad. I kept loosening the nuts and now they are just barely over finger tight and still a little bit of vibration. I bought lock tight, so if you guys don't think I ruined the joint, I will put it on 2-5 ftlbs with locktite to keep it on and drive it. U-joint has maybe 4-5 years and about 5k miles on it. I drew a line on my shaft to make sure it was put back on the way it came off, but I would be willing to rotate it 180 to see if it helps.
I've never had a u-joint give me issues because it was overtightened. It wouldn't hurt to replace the u-joint anyway...you might have one going out. Has the driveshaft been balanced recently? Does the yolk in the rear end look centered? I know, these things seem way out in left field, but it seems like an odd occurance.
Stock drive shaft never been balanced. This is a new problem after I put the shaft back on and drove it to get mufflers put on with them a little tight... It just seems that now I cannot get them loose enough, unless I have them too loose now...
Stupid question, but did you grease them? Sometimes out of the box they have little to no grease in them.
Did you install the driveline the same way it came out? If you turn it 180 degrees and then put it in does it still vibrate? Could the muffler guy have heated it with a torch when he was working on the exhaust?
On the way to the muffler shop, right after I put the shaft back in, it had open headers and I drove it 15 miles or so to the shop. It was vibrating really bad then, and I assumed it was the open headers resonating through the car. Then when the mufflers were installed, it still vibrated from 30mph or so on up. I mean RATTLING the doors vibrating... So I am pretty sure I oversnugged the bolts, but I don't mean major cranking on them. I have dealt with this before and know to use a light hand when tightening these things. But now I have them loose enough that the lock washers aren't even compressed to flat, and they are still vibrating. If it isn't raining, I may rotate the shaft 180 tomorrow and try again...It seems like I should be tighter than I am and should not be vibrating this badly.
I replaced many U joints and rarely ever marked the driveline. The nuts, hand tight...never a problem unless something happened like the time I accidently (not even sure I caused it) knocked off a weight. I had to replace my front yoke when the rubber went bad once...it vibrated pretty bad before the ring came completly off and spun around.
u joint problems hey scooper check the driveshaft, You said the car had a lean b4 you installed the caltracks and subframe connectors. did you jack the car up then installed the stuff or did you work your way under the car while it sat on your driveway and installed the stuff while the car was at a relaxed state. You have possible put the drivetrain in a bind and that is what is causign the vibration. I can assure you that if you loosen the caltracks and subframe connectors your vibe will go away unless you have a bad driveshaft and torqueing the ujoint caps is unnecessary in my opinion, just tightened them with a long wrench and forget the torque.
as Gene, said...i had a trans. mount do the same thing. thought it was a u-joint. don't know why leaving the nuts loose does anything. i have never tightened the nut with anything but a hand wrench...tight. ... ...
hey check the caps on the ujoints to c if they r bottomed out and the are on correctly maybe but highly doubtful.
If the weather holds out (doubtful) I will look into this issue more tomorrow. But, it is raining now, and is supposed to keep on doing so, so I doubt anything will surface tomorrow. As for the caltrac/subrames, I installed the subrames with all four wheels weighted, and set caltracs preload with weight on the wheels. the shaft came off when I was installing carpet so I could get to the nuts holding my shifter on. Put it back on and hand tightened it and that is when the vibe started. I put a paint line on it before I removed it to make sure it was back where it belonged. I think I need to drop the shaft and check the caps, then put it back on and make sure it is centered. then lightly tighten the nuts.
Another possibility is that the joint isn't seated in the yoke. Some of them have little tabs for locating the joint and I've had u-joints ride up on the tab before and due to that they were misaligned. The same thing could happen if either of your caps aren't fully seated. Good luck and let us know what you find!
I may have them loose enough that the caps are now traveling outward due to centrifugal (centripetal?) force. I will try to get under the car tomorrow and take a look. I was wondering...can I use the lock washer as a device to measure even torquing of the nuts? It seems that the space between the two "flaps" in the washer should seat to level at about the same low torque. Maybe tighten the nuts until all 4 washers no longer have that __-- on the edges and become __ __. That should be a very low torque, I can then continue to tighten one or two flats at a time on each nut until I get close to the low of 8 ft lbs. I am wondering if I am tightening them unevenly or just too much putting a bind on the caps. If I get one side of the strap to 8, then tighten the other to 8, it might be pulling the first one up to 15 or so (just one of those things I think too much about ) Either way, I am putting a good layer of locktite on tomorrow in case these work better with less torque, so they don't work their way off.
