BAD driveline vibration - Diagnosis? Tips?

[taxx]

So yesterday I drove back 6 hours straight on the interstate and the thing rode like a cadilac on 35s. Today I go to work and it is vibrating like all 4 tires are way out of balance, but it isn't that it is in the driveline. This is a 4wd second gen X with no front driveshaft. I crawled under the truck thinking I might see something and guess what.... I DID!

There is t-case fluid all over the back side of it. So I am thinking maybe it is a bearing problem on the output shaftof the t-case? Any way to correctly diagnose this problem? The rear gears are new (well they were) and broke in fine I really don't think it is in the rear axle, but the whole truck shakes especially my seat and floor when I am driving, the faster I go the worse it gets, When I let of fthe power it lets up a bit depending on speed, but is more noticiable under power. It literally feels like I am driving a giant vibrator.

Any ideas? anyone have any experience with these t-cases and the ease of diagnosing them / fixing them or should I check some other stuff out first?

 

[RiverRat]

Check out the motor and tranny mounts. The fluid leak doesn't sound good

I have never had a Xfr case apart so I can't help much there. You could check for a loose output shaft by wiggling it around.

 

[taxx]

no

I'll wiggle it sometime soon .

It isn't the mounts. They wouldn't have been fine just yesterday and then today be shot. Besides it is only when you have it in gear and are moving. It is dependednt on speed not RPMs.

I'll see it it will wiggle/.

 

[mrboyle]

Check the u-joints, make sure one didn't lock up.

 

[Lifted95X]

Originally posted by taxxman2k It literally feels like I am driving a giant vibrator.

Make the best of it!

 

[taxx]

will do.

I am gonna work from the rear forward. I am gonna change the fluid in the rear dif anyways, don't know how necessary that is with the new gears but I wanted to check so I'll start there then drop the shaft and check it then wiggle the output shaft....

 

[taxx]

Originally posted by mrboyle
Check the u-joints, make sure one didn't lock up.

That could cause that seal to go bad too I would think. It is very possible that a u-joint is locked up. Tat shaft sat for two years. Regarless it sounds like that output seal has to be replaced. Anyone ever done that? Is the output shaft easy top pull and put back in without messing anything up?

 

[TravisC]

I've got the same problem, although mine is a 92. I've got the same symptons as far as the vibration and letting off the gas and it will go away somewhat. And I think I've got a bit of a fluid leak in my t-case. I don't have a chance to check it right now cause it's at the shop getting the back brakes changed (wasn't about it do it myself). So if you find anything out keep us posted, I'm interested to see what it is. Thanks.

 

[Maniak]

TravisC,
Not sure if you found your fix yet, but it sounds like you have the same symptom as me..

1992 X, 4 door..
Picks up a vibration that you can feel @ about 35-40mph and higher..
If I get off the gas it pretty much goes away..

In my case, its the rear u-joints. I have one that if just about frozen (I can't move it by hand - even when the shaft is out of the truck)..

Its worth a check..

~Mark

 

[TravisC]

Originally posted by Maniak
TravisC,
Not sure if you found your fix yet, but it sounds like you have the same symptom as me..

1992 X, 4 door..
Picks up a vibration that you can feel @ about 35-40mph and higher..
If I get off the gas it pretty much goes away..

In my case, its the rear u-joints. I have one that if just about frozen (I can't move it by hand - even when the shaft is out of the truck)..

Its worth a check..

~Mark

Yeah I foundut what it was, the hard way http://www.explorerforum.com/forums/showthread.php?s=&threadid=82313

It sucked

 

[TheRookie]

hmm, i had this problem before my trans went. Havent had it to highway speed since i replaced it. Should have done the joints then. I was thinking that my problem may have been the torque converter lock up.

 

[Maniak]

ahh..

Sorry about the timing Travis, if I would have seen that thread maybe you could have caught it earlier. I only saw the thread because I was searching for the u-joint number since I knew mine was bad.

I'm glad only the drive shaft went with no major damage.. (I've heard of vehicles loosing the front u-joint on the rear shaft and then pole vaulting (flipping over)

~Mark

 

[TravisC]

Yeah, I think I was pretty luck, and so was the car behind me. I lost the rear u-joint and the it came apart at the spindles. I have no idea how it didn't hit the car behind me. Now I've got "heavy duty" u-joints in it

 

[X~FACTOR]

How do you go about checking if the U-Joint is frozen without actually taking it apart?

 

[Maniak]

I first just looked at my u-joints. One of them had a little gap between the cup and the joint (it just didn't look the same)...

At that point I took my driveshaft down, and then found that I couldn't move the rear u-joint on 1 axis.

~Mark

 

[kurant045]

I think all of us with 1st gen xplorers have this giant vibrator feeling on the highway

 

[X~FACTOR]

Thanks, Maniak.

Originally posted by kurant045
I think all of us with 1st gen xplorers have this giant vibrator feeling on the highway

Some say that isn't a bad thing.