In the last few days I've been getting this weird vibration problem with my 1994 pickup. When I'm on the highway it rumbles (sounds like I have big knobby tires) and vibrates enough to make a cup of coffee rotate in the cupholder. It'll do this under acceleration or while cruising, but if you let off the gas (ie the diff is pushing the motor now) it goes away. It'll come back if you gas up again, or put in the clutch.

I crawled under today and noticed a small leak coming from the tcase, checked the fluid and it was about 2-300cc low. Filled it up and no change. The u-joints are all tight.

A few weeks ago I went in for a safety and the shop didn't torque the rear driver wheel nuts. The wheel fell half-off (ie the lug nuts came off and the wheel came half-off with a bang) a few days later. Is it possible I bent the axle or something?

I'll check the diff fluid sometime soon and maybe pull the rear brakes and check everything out there...

Thanks for any input.

 

no ideas?

 

inspect and keep an eye on those lug studs. theyre probably damaged and if so will tend to loosen up over time even with the proper torque.

you sure you checked the u-joints? thats what it sounds like the issue is, and theres quite a few of em to check.

 

I wobbled every driveshaft and the only noticeable play was coming from the diff and tcase. The ujoints themselves had no play whatsoever. I should really take some time and jack up the rear end and check everything for play, too.

I gotta get a grease gun and I'll hit every grease point and maybe that'll help..