Vibration when driving

[Abom]

Ok, so I've searched for hours and can't find anything that pinpoints to my issue. So here we go:

About 2 months ago I started getting the squeeling, gear change "clunk" and nasty vibration that almost made my tilt steering permanent. Put the X on jackstands, rear driveshaft had a ton of play in it, obvious universals need to be replaced. Replaced those, X ran awesome and smooth as glass.

2 weeks ago, I started getting another vibration. Here's the symptoms:

a) occasionally, very occasionally (usually first thing in the morning), I'll get a soft "clunk" when shifting out of Park.
b) vibration is not usually felt the first 5 minutes of driving, or it's not as prominent.
c) the vibration feels the same as before (before the rear universals were changed), but maybe only half as bad.
d) happens at any speed and any RPM, and on any road (I ruled out a frost heaved road or anything).
d) X must be moving to feel it, if I'm at idle and rev the engine (in either neutral or drive with my foot on the brake), I don't feel it.
e) putting the tranny into neutral while driving makes no difference, same vibration.
f) X can be in 2wd, or 4auto, same vibration in both modes. Seems to be ever so slightly worse in 4auto, although it's possible that's just more normal vibration from the front driveshaft now spinning as well.
g) it feels as if the entire vehicle is shaking left and right very quickly, not extreme, but definately noticeable.
h) vibration can be felt in the steering wheel, but nothing like when the rear driveshaft universals were toast.
i) no strange noises, no squeeling, no metal-on-metal grinding sounds.


Front driveshaft seems OK, not a whole lot of play (checked it when I did the rear driveshaft), but the front universals are still as old as the truck.

I had the wheels balanced when I got new tires last year, and like I said, it ran smooth right after the rear universals were changed.

I've looked all over and don't see anything broken / loose, aside from my leaking pinion seal on my front diff where the front driveshaft goes in. Can this be related at all ?

OK, if I missed anything, please ask, this is extremely frustrating and I really don't want to have to resort to going to the garage, minimum 2 hour labour time for diagnosing @ $95 / hour

 

[skoal_mint]

well if you can put the read on stands and get the tires going you might be able to find find your problem better.

I dont know if yours is a true 2wd, so dont do it unless it is, or you did the brown wire mod

 

[Abom]

well if you can put the read on stands and get the tires going you might be able to find find your problem better.

I dont know if yours is a true 2wd, so dont do it unless it is, or you did the brown wire mod

Mine is true 2wd, I have the front centre axel disconnect.

What do you suggest I check while the rear is on stands ? I can certainly do this, but what am I looking for ?

 

[skoal_mint]

Check the entire driveline. Look for any movement, listen for any sounds. Its like playing marco, polo...hear the sound and goto the sound, if it will do it.

Maybe their might be a bad bearing somewhere. last month i noticed that my transfer case output seal was leaking, i pushed up on the driveshaft and found out that my bearing was shot, might explain why my explorer would vibrate lots at high speeds.

Good luck, i know it can be really hard to pin point a problem

 

[adivorcedsin]

I'm having the same problem with mine....One thing I did notice is that I have a p/s leak on my return line and possibly air in the line...My mom's buick century had the same problem a few months ago and it was cured by fixing the leak. My recommendation, cheack ur p/s for air in the lines...