Howdy all Yotaers out there, my truck has recently picked up an odd habbit. When accelerating from a stop the whole truck (mostly the front end I think, though) vibrates violently until I reach about 15 mph or let off the gas, then It runs smooth at all engine revs and speeds. engine mounts are fine, I just rotated my tires, Ball joints are recently replaced.

It is an 86' pickup rwd and 22re.

any help you guys can provide will be much appreciated

 

Do a search here on "death wobble"
This may be your problem. At least a place to start looking.

 

did you have the driveshaft off? out of phase ujoints can feel like that

 

I'm thinking U-joints myself, and probably going to replace the center bearing and bushing.

 

I've done quite a bit of research out there and everyone who had driveline problems didn't have the bad vibrations until at least 40 mph, is this something that could really present a problem at 10 to 15 mph? I guess I'm just having trouble understanding why this problem presents itself at low speeds and not at any higher speeds.

 

If it's a 5 spd push in the clutch when it acts up and start coasting. If it goes away you might want to look at your clutch.

 

It is an auto 4 speed with O/D (which doesn't work, but that is for another thread)

 

So looks like there are 3 u joints under there, any thoughts on how to tell which one is bad? none of them feel loose.