I posted earlier about getting a new front u-joint installed in my daily driver Caprice. Well, I did and everything seemed fine at first. Then I noticed there was still a little vibration around 40 mph, like there was before had the joint replaced, but now it was much less severe. That was on day 1. On day 2 the 40 mph vibration went away, but then I started to notice an irritating shake at high speeds like 55 to 65 mph, but only sometimes. Sort of like an out-of-round tire. Thinking the u-joint might not be tight, or not lubed, or who knows what, I got under the car and checked it. Here's what I found. SUre enough, a nice new shiny silver u-joint is in there, and even has a grease fitting. There was gray grease coming out of the joint. I tried jostling the joint by grabbing the shaft and shaking it sideways, and was able to get a clicking sound, and it looked like the joint was moving a little bit, like 1/32 of an inch. Later the same day I tried it again and this time I couldn't get any clicking sound, and no movement from the joint. Also, the driveshaft would not rotate at all this time, as it had rotated about a quarter of an inch the first time, each direction. Both times I had the car in Park, but the first time I had the left front tire up on a board so I could get better access. Some people have told me there should be absolutlely no play in a ujoint, and all sorts of horrible things could happen, such as the joint exploding. I want to drive it some more and see if it "breaks in". Maybe the old yoke is worn and the new u-joint doesn't fit exactly right and needs to "break in". He left the old yoke on, and just put in the new u-joint, then test drove it.
Should I not drive the car at all? I've put about 220 miles on it with the new joint. I fugure if there really is a problem with the new u-joint, I'll get some warning such as a vibration, and then I can take it back to the mech with an obvious problem. I also want to figure out if the high speed shake is u-joint related, before I take the car back. What do you guys think, can I drive it like this ? How much u-joint play is OK, and why did the driveshaft not move at all once, and move a quarter of an inch the other time ?? I wish this were simpler, just get a new u-joint and have evreything smooth and fine, but no....



[This message has been edited by GTA88 (edited December 09, 2001).]