Vibration issues, need help.

[Jack5219]

I'm new to this forum, new to owning an explorer and a bit new to the DIY auto repair. I recently bought a 94 X sport 4x4 with a manuel trans. It runs great with only one problem. Whenever it gets up around 65 mph it gets a really bad vibration. It gets worse the faster it goes. If I take my foot off the gas it's still there. The vibration only goes away when the truck slows. It is the same in 4th gear and in overdrive. It seems to be worse on bumpy or uneven pavement. In the last month I have replaced all 4 shocks, replaced the rear leaf spring shackles, and repacked and tightened the front wheel bearings. I checked the drive shaft, the u-joints seem good and spug although I did notice a slight leek in the rear dif behind the pinion flange. Nothing seems to be helping. Does anyone have an idea what could be causing the vibration?

 

[1badnevergo]

There are to many issues that can be the problem starting with front wheel alignment make sure its right if the vibration is in the steering wheel if its in the seat area its coming from the rear of the vehicle check all four tires for balance and rim damage also a warped rim will balance out but cause a vibration to check to make sure the tires aren't directional if they are they should all have the arrows facing the front of the vehicle also if the person you got the vehicle from never rotated the tires that will cause a vibration to then check the radius arm bushings as well as they are what causes death wobble

 

[Jack5219]

Thanks for the advice. I forgot to mention that I did have all 4 tires rotated and balanced at a shop and it didn't help. I did notice a gap between the radius arm bushing and the frame, about a 1/4'-1/2' on the right side the left is not quite as bad but still has a gap. Are these supposed to be tight? Could that be causing my problem? Also What is the death wobble? I have seen it mentioned in other threads but don't know what it is. Thanks again.

 

[1badnevergo]

There isn't supposed to be a gap on the radius arm bushings also death wobble is where the bushings have gone bad and allow the wheel to move in the pocket so to speak and it gets worse the faster you drive