Driveline vibes??

Hey guys, not sure about this one. I installed a R.E 3.5 super flex lift a month ago. After the install I noticed some noise from the transfer case during decel so I installed a t-case drop, problem solved! I was running 75-80 mph with no noise or vibes. I just had my new wheels and tires mounted and when I reach about 53 mph and everything gets shaky. I took them back to the tire store to have them check the balance and 2 tires where a little off. I left the shop hoping all was good but again vibes at 55mph or so. My question is can this be something else? The u-joints seemed tight but I will need to shim the rear a little I noticed.

89 XJer said:

when I reach about 53 mph and everything gets shaky. I took them back to the tire store to have them check the balance and 2 tires where a little off. I left the shop hoping all was good but again vibes at 55mph or so. My question is can this be something else?

Click to expand...

do a search on the forum for "death wobble." There are as many solutions are there are cause/effects. Due to the fact that your post is a little hazy on details pertaining to the location of the "shake" that was a quick guess. Now that I re-read your post, you are talking about your driveline? is it balanced? way to much grey area here......Can you be a little more specific.....

It seems to be coming from the front but I am not completelety sure. I really thought it would be the wheels because when I had the little 215's on it ran 75-80 mph with no problems at all after the lift and alignment.

At that speed, it sounds more like a balancing issue. Swap the tires front to rear and see if that helps. IF it does, then the tires that were in front were the problem. Don't know what tires you have, but some have troubles balancing, like BFG AT's and super swampers. The other problem could be an out of round tire. You can balance an out of round tire all day long and still get a shimmy. Move your tires around to try and narrow down which tire(s) may be the problem, then get it checked if it is out of round, or just get it warranteed and have them replace it anyways.
Just my $.02.

What size tires did you mount up. Could it be that bulkier tires could have brought on new problems that the smaller ones did not. ex. loose steering components, trackbar, etc...

I mounted 31x10.50x15 BFG AT's on black rockcrawler rims 15x7