91 K-1500 Severe vibration in 4WD system
 

I have 1991 chevy k1500 pick up and i replaced the front U-joint at the front diff and put a 4WD actuator eliminator in and got a severe vibration at about 60km/ph in 2High, would it be possible my front and read drive shafts are out of phase? Also replaced my transfer case with one from a wrecker about 6 months ago (it had 90 days warranty) but never had 4WD i just figured it was the actuator, if i put it in 4High with the original actuator still had vibration, with the eliminator it does it even in 2High. Where would the vibration more likely be coming from the transfer case, the drive shaft, the front diff or possibly c-v joints or hub? Also noticed a leak at my passenger side c-v joint, I read somewhere else that In 2High with the thermal actuator in the front passenger side spins free, is there anyway to test it?

Well, as far as I know, 2wd means your front driveshaft shouldn't be spinning ... so probably not the cause of the vibration. Check your rear driveshaft U joints.

I did, Im pretty sure with the actuator eliminator in it the motion of the front tires will still cause the front drive shaft to spin it just wont be engaged in the transfer case until I pull the lever, I think if it where in fact the rear u joints it would vibrate with the original thermal actuator, would it not?

If it were the rear drive shaft, it will vibrate in 2wd, 4x4 or any time the truck moves. The rear driveshaft is never not spinning or being driven by the transfer case.

Obviously, But it will not do it when the original thermal actuator is in even in 2 high so that isn't the problem.

Im now thinking it is in the front drive shaft some where

The front shaft does not move when the truck is in 2wd.

The front drive shaft does turn when the actuator eliminator is it because it locks the diff in and leaves the 4wd engagement strictly to the transfer case instead of the thermal actuator and transfer case, Ergo the forward motion of the front tires while i'm driving causes the front driveshaft to turn. I figured out it was my slip yolk, it had over 1/8 of an inch of play in it. Thanks for but you guys are slightly useless.

So what do you think this is anyways? Last I checked, this was a very small community of people who work on our trucks and post here in an effort to help other people who ask for help. What, is it like you deserve an answer from us? This isn't a service, here. Go ask questions elsewhere if you aren't happy with out posts here. Nobody asked you to use the forum.

If your front drive shaft is turning, something is messed up in the front end. There is a silinoid on the axle to disengage the drive shaft.

And don't be causing trouble. You are the one asking dumb questions. It's hard for us to tell without the truck in front of you. We are taking guesses. If you wanna be a smart jackass, go do it somewhere else.