Searched the forums and nothing really matched my issue exactly, some came close, but not quite so here goes:

I have 4wd 98 XJ, 2" coil spacers lift in front. I get vibration in the entire vehicle at 50 to 60 mph, and its worse in curves. The vibration comes back at 75mph and higher speeds on the interstate, again worse in curves. Don't notice the vibration or noise at all at lower speeds.

I am thinking front wheel hubs, or maybe front axle u-joints. I hear metal clicking when pulling out from stop or turning while pulling out. I read some forums that say it could be anything thing in the drive line from the transfer case to the wheel balance. How do I know where to start without sinking $200+ for some timken wheel hubs and not fixing the problem? I am pretty sure the wheel hubs are the original, and I have 155k miles on them so probably should be changed anyway. But I don't want to spend money on something that should fix my problem, and then it doesn't fix my problem. My tires are worn and need to be replaced, but I recently had them balanced and rotated with no change. I changed the rear drive shaft u-joints about 3 years ago, so i don't think it is rear driveline noise/vibration. Also replaced rear axle bearings and put good new fluid in the rear differential. Had the problem before I swapped the rear bearings so I am pretty sure I didn't screw up the rear. Also, I have the spacer bars installed on the transmission crossmember to drop the transmission down and not cause such a bad angle on the u-joints.

Any Ideas?

 

These are the things i would check, in this order:

-track bar
-axle u-joints
-front driveshaft u-joints
-the 3 steering tre's
-ball joints
-wheel bearings
-control arm bushings

 

Few things.
1. U joints could still be shot if crappy ones were installed before. Easy way to tell, pop the jeep in neutral then get underneath (plz don't be part of Darwin's theory, use wheel chalks) move the driveshaft around at the u joint in all different directions. If theirs any play you need to change em. Even a tiny bit can cause vibrations. Same thing can be done with the front wheel joints.
2. Jack the front up till the tires come off the ground. Put your hand at 12 and 6 on the tire and move it back and forth. If theirs excessive play or movement then yes you need to replace it. Not a full proof way of checking but it's easy.
3. Also while it's on the ground check any loose or warn steering comments. Mostly the track bar and tie rods. Basically just grab hold and start jiggling it. If it has play, replace it.
4. I know some other threads don't have the "exact" thing your looking for but I know all these suggestions and more are located in the forums and a simple google search provided me with ad least 3 other good resources that all suggest the same thing and more. Not to be a dick or anything but you'll almost never find the perfect answer and solution. Sometimes you have to do some research and think for yourself.

-Andrew

 

I have the same exact symptoms (still) on my 89 renix cherokee 4.0 aw4.

Replaced:
Track bar, tie rods, steering stabilizer, front axle u joints, rear driveshaft u joints, driver's side steering knuckle and ball joints (all moog), wheel hub/bearings tires rotated and balanced (they're still good tread, but they are oversized and could still be the issue).

So far, the wobble has been greatly reduced since when I first got it, but once it hits 55, the shimmy will always be there. Not terrible, but definitely there.

Things I have left to change:
Front driveshaft Ujoints (this week)
Shocks (asap)
Lower and Upper Control Arms (last, if problem is still there)


Never has any issues 0-50, drives rock solid (still notice some slight "clunky/clicky" noise that sound like U joints, but pretty sure it's the front driveshaft ones which I am doing this week, it better not be the front ones which I already did recently.) Though I think there will always be SOME axle noise, I guess I'll see when I rip the front driveshaft out.

 

OP, few things. First, just take your front DS off with 8mm wrench. Go for a drive and report back.

Also, do you feel the steering wheel jerk on turns. When you hit bumps. The metal sound can be a bad axle u joint and the metal clip might be broken and there is movement in the joint. This you can just crawl under and move around. Like stated above. Shouldn't be any movement. Is you rear lifted...or did you just lift the front?

 

Rear is lifted, i think with 2" shackles and also has an extra leaf added, so it sits higher than the front. I rescued this jeep from the original owner and it was already lifted when i got it, with nothing done other than the lift added. I have repaired the rear shock mounts, replaced the original shocks with longer travel shocks, replaced the rear drive shaft u joints, replaced rear brake cylinders, replaced rear axle bearings and changed diff fluid, added the spacers to the trans cross member that should have been installed when the lift was done, replaced the track bar(this got rid of the death wobble for me), replaced oil filter adapter seal, and repaired a big rust hole in drivers floor pan. So yeah, it has been a project.

Now that you mention it, I do feel a slight jerk sometimes in slow speed sharp turns. But nothing like that hard jerking when you have the 4wd engaged and you crank the wheel too sharp.

How fast can I drive with the front drive shaft removed? is it going to sling diff fluid or transmission fluid out or cause any issues at high speeds? Probably a stupid question, but I have never really looked at the front drive shaft to get familiar with it. I see your logic though. If I remove the shaft, and the vibration goes away, then the shaft's ujoints are the problem or the shaft may be bent. If the vibrations stay, then its got to be the front axle ujoints or wheel hubs, right? Am I tracking true here?

 

You can max the speedo out without the front driveshaft in 2wd and in 4hi. And yes, if the vibrations stop with DS removed, that's the issue.

Now as for the jerk, check the axle u joints for movement.

With your rear being lifted probably 4", there's chance your rear DS is fudged up.

Did the vibrations just start. Is this the first time you driving the jeep after rescuing it. Does it have a TC drop or SYE. There's a chance that there's more than one issue and it a coincidence that the metal sound and the vibrations.

 

Transmission has 2, may 1 1/2" drop spacers on the cross member. Vibration did not just start. Just has gradually gotten worse over about a year. Is there a way i can determine exactly how much lift i have on the rear? original owner said he had an extra leaf added to make it sit higher in the rear because he thought "it looked better". I totally disagree and would like to make it same as the front.

I will try the front DS removal test this weekend and let you know what I find.

 

Another question about checking for ujoint play. Do I twist it radially and see if it has slop, or do I push on the drive shaft in an upward direction like I am trying to push it thru the floor pans, and sideways like towards the wheels?

 

With the driveshaft ones, it might be a bit tricky to see a lot of play, but you should be able to see any with attempting to rotate them or grabbing the driveshafts and trying to shake them hard (you shouldn't be able to) - but the front axle u joints are a bit easier to see slop in them - jack up the axle and get the wheels off the ground (chock back wheels) - rotate the tires by hand while looking under (from the back of the wheel) at the u joints - when you go from one direction back to the next, if there is a lot of slop (like mine had) you will see a noticeable CLUNK when the axle changes rotation directions. It's actually very easy to see.

Like I said, the axle u joints are a lot easier to notice slop than driveshaft ones (unless they're really bad, but I've never seen really bad driveshaft u joints, but of course it's possible). My original 89's in the front axle were SHOT, but the ones I pulled out of the back driveshaft weren't actually that bad at all, but were worth doing (the back driveshaft is really easy to get in and out.)

Now I just have to do the front one, so I'll be in the same boat as you will be (I'll be ripping the front driveshaft out tonight or tomorrow.)

 

For the axles, check for discoloration for overheating and for play from u joint cap to cap. No rotating or in and out.

 

Ok, so, i didn't get the time to remove the front drive shaft this weekend. But I did crawl underneath and yank around on it. I pushed up, like I was trying to benchpress the jeep, no play whatsoever in the shaft. I pushed side to side toward the engine and then pulled outward toward the driver's door, no play whatsoever. How much force does it take to see the play in the front shaft u-joints? Is it safe to assume the front shaft is ok? I was actually lifting the jeep up off the shock absorbers little cause the frame moved slightly when i pushed up, but the shaft was rock solid. No movement of anything when i was pushing side to side. Should I move on to the front axel u-joints?

 

I was having a similar problem to the OP, posted about it here.

https://www.cherokeeforum.com/f2/wha...g-type-197386/

I have some photos there of my axle ujoints, and there was no play in them when installed, but once out you could hold the shaft level and the hub would not even droop because the joints were frozen. You could push on them and move them maybe 20 degrees but beyond that it was difficult. So they can be frozen up without much slack in them.

 

Yup and that's where you typically get the jerking steering wheel in low speed turns.

 

For the front axle u joints you need to try to see if there's play right at the end of the axle (that is inside the tube) right at the u joints. I actually realized the other day I lost a C clip off one of my u joints (I learned the hard way that you should always chase c clips with a drift or chisel to seat them good after installing them) - luckily the cap didn't back all the way out , but it did a little bit - so I had a lot of play in the axle shaft. Tapped it back in with a hammer and got the c clip on there real good, solved a lot of my wobble that I had (after already fixing the u joints) - but there's still a bit of a shimmy at 55+, but it's now even less.

Again like I said you can kind of test them with the axle jacked up and rotating the tires by hand and watching the u joints from underneath.

If they are old, they're probably worth doing regardless. There's a ton of good writeups about them - and I will highly recommend using the socket + power steering method to pop the hubs off, works like a charm. Only PIA is having a giant 36mm socket for the wheels. And don't forget to have the C clips on there good and tight, and tap them good with a chisel/flathead/etc.

For me it's either driveshaft ujoints, shocks, LCA's, or just wheels/tires (which I suspect to be at least some of the wobble, even though they've been rotated and balanced, I don't really trust them, and they're slightly oversized)