U joints.

Greg,

Unexplained vibes is a big indicator. Block the wheels and climb under there. Rotate the shaft back and fourth and look for slop in the joints. It's $10 for two new joints and takes around 10-15 minutes to change for an experianced person, 45 for a first-timer. They probably need it.

Carl

Hi Carl. Thanks for the advice. Makes sense. My other question is then, I just bought an 86 XJ and with it the guy threw in 4 brand new u joints!! Are they universal to Jeeps, say YJ to XJ ?

Greg

I do not know if they cross between the 84-86 XJ's and later models, but AFAIK the rear u-joints, front u-joints and front axle u-joints are all the same part number for 87-01 XJ's, all YJ's and TJ's. (D35 axle).

Carl

Well I just went out and climed under it. No noticeable play but that doesn't mean that there isn't any right?

Greg

How about the rust? I would go ahead and replace 'em anyway if you don't know when they were last replaced.

Carl

No rust seeping that I saw, it appeared very dry. I am getting some vibration thru the steering wheel and shifter. When I depress the clutch or let off the gas, it stops. It seems to be getting worse. I thought maybe the u joints, but maybe a slipping clutch? I don't know, guess I'll have to take it to my mechanic. I really hate doing that! It has a 5 speed and about 80k miles on it.

Greg

Should my Jeep be in gear when I perform this test?

Greg

Yes, the jeep should be in gear. Check out your front end and tire balance if you are getting a steering wheel vibe.

Carl

Why when I let off the gas or depress the clutch does it stop. That wouldn't be unbalanced tires or front end probs wpuld it?

Greg

Also feel it in the shifter as well.

Greg

Hey Carl, just went out again and checked for side play. Clicking sound and about 1/16 play. I think its toast. Thanks for the help!

Greg

Carl

Its in the joint

Due for a replacement. Be sure you get the greaseable kind, and not the needle fitting.

Carl

Lateral slop

Yes I am afraid thats what it is. It is terribly obvious. If you could only see what I see!!

Greg

The best way to tell is to take off the drive shaft (not that hard) and feel for roughness or slop in the joints. They can feel nice and tight when you crawl under the vehicle, but if they are starting to seize up they will get loose pretty quick. One good thing is that the drive shaft is (theoretically) too short to pole vault your vehicle that far when the front joint breaks, and Myth Busters debunked that one anyway.

The vibration stopping "when I let off the gas or depress the clutch" is a pretty good sign of a bad U-joint.

Earle

When I went to Canadian Tire for my first U joint, computer said, " fits jeep, 1946 to 2001" they were looking under 81 CJ7 so don't know if that goes for the bigger jeeps or not, thought it was funny though. But I do know