u joints

[YJReed]

Well, sorry if it is a stupid question but, i am trying to buy new u joints, i have loud clunks, and a jerk when i turn and it is the only thing i can think of to change, but i dont know the difference between axle u joints and drive line u joints on my 93 YJ.
thanks for the help
glenn

[inVERt'D]

Not a stupid question, but forgive this one: you're not driving in 4wd on dry pavement, are you?

Assuming you have the stock axles, the ujoints will be Spicer 5-260X or equivalent. These have a cap diameter of 1-1/16". If you have later model axles, such as those found in the TJs, they could be the somewhat larger 5-297X or 5-760X. These both have a cap diameter of 1-3/16". These two are interchangeable, but the 760s are rated as the more durable of the two.

Your stock driveshafts would have Spicer 5-153X, aka "1310" u-joints.

[YJReed]

well, the answer to your qustion could be yes and no i am not sure... i have the transfer case in 2H however my 4WD dash light has been lit up, so i guess it could be in 4WD, didnt really think about it cuz my YJ has so many electrical grimlins i just thought it was one but mabey my hubs are not disengaging.

[Lumpy Grits]

Have you checked the "U" joints for slop?
Why do you think their bad?
Find out what really is wrong before you start just throw'n $$$ away.
LG

[inVERt'D]

LG, you have a good point, but if you have 260 u-joints and you think they're bad, they probably are. If you don't think they're bad, you're probably their mother.

Glenn, your YJ doesn't have hubs, unless someone put em on there, and if they did, I'm sure they'd be the manual kind. Instead of locking hubs, YJs came with a two-piece passenger-side axle that is vacuum-engaged. It was a neat idea, but not a very good one.

It would be very helpful at this stage to ascertain wtf is going on. From what you've indicated, you have experienced the aforementioned problem while in motion. Could be the steering gearbox is loose. You could have other loose or broken parts and your rig could be in 4wd. You have a 1.5" body lift, so your transfer case linkage is suspect.

I suggest the following minimum load-out for operation wtf: floor jack (1), jack stands (4), helper (1). If your helper is mechanically inclined, good. Knowledgeable in the ways of Jeep YJs, better. Capable of turning the steering wheel while you're in front of the Jeep looking and listening, acceptable.

Okay, so there are two at least two of you. Have the least knowledgeable sitting in the Jeep, turning the steering wheel on command. Start with the Jeep on the ground and stationary. Have steering wheel operator turn the wheel lock-to-lock while forward observer makes note of any suspicious sounds or movement. Check out the steering gearbox for sure. The pitman arm should move, the box should not. Note any slop in the steering linkages and tie rod ends as well. Check out the knuckle ball joints, u-joints, etc. You can try prying on the u-joints with a small pry bar. They shouldn't move.

Next, jack the front of the Jeep up enough so that the weight is off the front tires. Try to wiggle and shake the wheels back and forth, up and down. They should not move without moving the steering wheel too. If they do, it's likely you need new ball joints. That would sound clunky, wouldn't cause a clunk-jerk when you're driving. With your rig in 4wd, in gear, engine off, try to twist the tires forward and back looking for play in the u-joints.

Alright, next put the Jeep on jackstands with all 4 tires off the ground. Stands under the axles will probably work best. Put the transfer case shifter back to the 2 Hi position. Your objective here will be to determine whether or not the rig is actually in 4wd when the shift lever thinks it's not. One or more front wheels spinning under power would indicate a positive. While we are primarily concerned with front end, do not attempt this maneuver with the rear tires on the ground.

By now you should have found one or more problems. If those problems include the rig being in 4wd, then you have a problem with your t-case shift linkage, which, given your body lift, would not be surprising. At any rate, report your observations in this thread at your earliest convenience. I didn't type all this crap because I like to hear my keyboard go clackety-clack. Place all 4 tires back on the ground before attempting to drive the vehicle.

[YJReed]

thanks for the help, i will get on that this sunday, but i do have some info to through at you, you got my brain turning and i have more background... I recentyly dropped a newly rebuilt 4.0 in after a failed 4.7 project... BTW if any one has any small claim court expertece i am all ears... any who, maybe i conected my vacume lines incorectly and i have 4WD constently ingaged because of that? and all of my tie rod ends are shot, i already have new ones on order, they should be here today and those will be instaled on sunday as well, and than i will continue your test.

if the new info helps you help me let me know.
thanks agian
glenn

[inVERt'D]

Sorry to hear about your failed 4.7 project. The vacuum lines by themselves couldn't put your rig into 4wd; they could only engage the front axle.
If your t-case was in 2wd and your front axle engaged, your YJ would function the same as a TJ in 2wd, which does not have a vacuum disconnect axle--it has a 1-piece inner axle shaft. To get power to the front wheels, your t-case must be in 4 Hi or 4 Lo AND your front axle must be engaged.

(BTW, TJ shafts would be a good, easy upgrade, and I think others have posted threads on this forum about how to do that.)

Now if your t-case was in 4wd, but your front axle was disconnected, your Jeep would behave more or less as if it were in 2wd--your front wheel drive wouldn't work. This is a common problem for YJs.

The 4WD light is wired to a sensor on your t-case. The fact that it's on would lead me to suspect that your t-case is, in fact, in 4 Hi. The jerk you're describing also sounds like a vehicle which is in 4wd on dry pavement, but obviously that's coming from someone who can't see, hear, or feel what's actually going on.

If you do have a vacuum problem with the axle, the best and most permanent way to fix it would be to get rid of it, and do the TJ axle upgrade I mentioned above.

Don't forget to check your steering gear.

Keep us posted.