sgt_why

Hello everyone!

I have a 1992 Jeep Cherokee with a Rubicon Express 3.5" lift. Have had the lift on it for about a year now, w/ no complaints.

Just a couple weeks ago, I replaced the stock (29x8.5) tires with a set of (4) Green Diamond Icelander M/Ts ... 31x10.5r15

For the first (4) days, everything was great! Had the tires mounted, balanced and my alignment done all at once.

Then I took it off-road through some mud and dirt trails -- to test out the new traction. (which I had already done a couple times since installing the tires)

When heading home, it started getting some serious vibration which at first seemed to come from the drive line ... then it "moved" to the center of the Jeep and the front end. And stayed in the front-end from then on-ward.

I had the tires re-balanced and the alignment checked, but they were OK.

It seemed to happen everytime now when I hit about 35mph, the front end starts vibrating and increases in pitch to the extent I have to pull over for fear of loosing control. Feels like the front tires are going to come flying off!

At first, thought maybe it was my brakes sticking causing the vibration -- because I had problems a few months back and had replaced the calipers and rotors on the front. No problems from the back end. However, I bled the front brakes on both sides and other than a little dirt in the oil everything seemed ok.

I went to Olympic 4x4 in Snohomish thinking I'd buy a new power brake booster/master cylinder and see if that helped. When I explained the problem, they said right away it was "DEATH WOBBLE" ... and that it was likely front worn tire rod ends, track bar and/or the steering stabilizer.

They talked me into buying a new heavy duty "Carrie" front suspension, including new adjustable tie rods and adj. track bar. Also picked up a new steering stabilizer as well.

After a weekend tearing out the old tie rods and drilling a 5/8" hole for the new track bar ... I thought the problem was solved.

But when test driving it, the "wobble" was only very slightly diminished. Still happens at ~35 MPH and feels like the wheels are going to rip off the Jeep.

So, I brought it back in to Les Schwab and had them check the front-end alignment and adjust the tie rods if necessary (since I had only eye-balled the adjustments when I put the new ones in). 2 hours later, they took my $55 and said that it was OK and that the tie rods hadn't needed adjusting.

I did some searching around and can't decide what to do next ...

- balanced the tires
- aligned front end
- replaced steering stabilizer (w/ Rancho)
- replaced tie rod ends
- installed new, adjustable track bar (Rubicon Express one)

Everything else under the Jeep looks like brand new -- so I'm at a loss what could be causing all this and why its so extreme.

Most others that complain of DW make it sound like it only happens after they hit a bump or something ... but the DW happens to me ONLY when accelerating towards 35 MPH -- if I push in the clutch, NO vibration.

Any suggestions out there ?

Will I have to replace part by part until the problem just goes away ??

Is there any hope ???
*sigh*

Kyle

its either your alignment or unbalanced tires hands down. everything leads to that. go outside and grab a measuring tape. measure your rear tires from inside of the tire on one side to the inside of the tire on the other side. remember that number.

now go to your front tires and do the same thing but for both the front and the rear of the axle tube, those two numbers should be very close to your rear end measurement. if they arent then you have an alignment issue. otherwise its a tire balance issue, but i will put my money on alignment.

-Kyle

sgt_why

Thanks for the speedy response!

I just measured it all and it does look odd --

REAR Axle (tire to tire)
4' 2.75"

FRONT Axle
6" in front == 4' 2.75"
6" behind == 4' 3.25" (+0.5" wider)

So this confirms your idea ... Would it be worthwhile to go back to Les Schwab and tell them to adjust it ? I wouldn't know what to tell them they "forgot to do."

Or take it to a specialty shop ?

ecksjay

i would try the balance first. It happened to me and the balance was the "magic bullet." I had tried an alignment and it helped a little then I did the balance and it went away.

Kyle

read this over and see if that helps you. but yes it is off and needs to be adjusted.

http://www.go.jeep-xj.info/HowtoAlignment.htm

-Kyle

sgt_why

Thanks, thats already made a huge difference ... still vibration at 35-45mph but its no longer "Death wobble" equiv.

I just adjusted the tie rods out about 3/4 of a rotation and tightened it back up ... and the toe is only about 1/8" or so instead of 1/2" it was before.
(these are after market tie-rods, sold by "carrie" ... about 2-3 times thicker than the stock ones and the drag link is angled as well)

I'll take another look tomorrow in daylight and check the camber/caster.

I'm curious -- did you need a SYE for your rig ?

Seems you have the similar RE 3.5" lift and 31x10.5 tires ... even RE Adj Trac Bar ... Except I used the RE 4.5" leaf spring pack on the rear after trying the add-a-leaf option -- stock leaves were too shot, so it didn't give me any lift.

Kyle

well im using a TC drop at the moment but i have the SYE sitting in my garage waiting for me to put it in. so to answer your question, yes i had vibes and still have some small ones which is why i have the SYE going on. but i would recommend a SYE for any XJ with lift, its just easier and takes care of the problem for good.

-Kyle

muddeprived

In order to track down a wobble, you need to make a list of possible culprits and then eliminate them. You got most of the common culprits eliminated but two others i thought of weren't on your list: driveshaft and tire rotation.

You can remove the front shaft and drive to eliminate it as the culprit. Last year my tj had a bad wobble after wheeling and it was my shaft getting bent on a mound. Also check into the rear too.

Rotate the front tires to the back and see if that does anything.

The thing with a wobble is that most of the time it's caused by more than one part. When it happens, the user starts looking for a single problem when it could be multiple parts playing a role.

Another thing to think about is MUD. Mud can get up into things and cause issues so clean out every drop of mud out of bearings/rotors/wheels/clutch, etc.....

sgt_why

Thanks for all the suggestions!

After adjusting the toe in by turning the tie-rod ends, I test drove it and the huge vibration in the front is about 70% better now.

But I noticed vibration in the drive line / rear end as well ... took another look today in day light and found that the vibration had caused the bottom (2) leafs on the rear to "shift" diagonally ... ie. the front of them went to the passenger side and the back ends towards the drivers side.

Wierd. It wasnt like this a day or so ago, so I'm assuming its a result of the vibration. Im running the RE 4.5" rear leaf pack ... which I had assumed was "heavy duty" ... I'll have to make/find something to hold those bottom 2 leafs in place.

Maybe it makes sense though, based on the alignment etc being off ? like the Jeep was trying to go straight but the back end is pointing to one side ... causing this kind of "tweaking".

I'm definitely realizing that its not "1" problem but more like the "straw on the camels back" ... so no doubt there are more problems to uncover.

Kyle

glad your problem is getting better, if you have any further questions please feel free to let us know.

-Kyle

sgt_why

I spent a bit more time on it today.

The toe is about 1/8" or less ... Camber at the suggested 87.5* (was surprised that I didn't need to make any adjustments here, there are already shims in place possibly from the factory)

Also pounded the bottom 2 leafs back in place and added another clamp to hold them.

As I was finishing up, realized the exhaust near the back of the cat had popped out of the rubber mount and was rubbing on the transmission. Put it back in place.

Aired the tires up to 40 psi to diminish their contact w/ the road as suggested ...

After all that ... took it for another drive. From 35-45mph there is a vibration feeling like driving over those dozer tracks on the side of the highway. But at higher speeds, it seems to smooth back out.

I'll try balancing the tires again and see if there is any more improvement.

sgt_why

Hello all! I picked up the Advance Adapters SYE kit and a new driveline from Tom Woods.

I had it all back together and then realized I couldnt get it to shift out of NUETRAL. Although the t-case lever was at 4 Lo.

So, I broke the cover open again ... and manually shifted it into 4LO.
Or so I think ...

Looking at the insides of the t-case, I could see where the linkage connects and shifts into each gear. (2h, 4h, 4l)

At first I thought it needed to be shifted all the way down, to the bottom of the "channel" to be 4LO. The "range adjustment plate" fits nicely over the pin on the outside of the tcase ... but once I tightened it up, it wouldnt move again.

Seems I had reversed it ? So, using a adj wrench I shifted the tcase to the opposite end of the channel ... the top inside. Once again, I was hoping this would be 4LO.

I loosened up the adjuster for the linkage .... but it just won't line up. Its just a hair off. If I shift it manually with the wrench one "click" the plate fits. But visually it appears I would now be in 4H .... (assuming 4Lo at one end, 2h at other)

Can anyone clarify ... if you're looking at the back of the transfer case w/o cover removed ... is 4LO the upper or lower reach of the linkage channel ?

Any other ideas as to why its giving me such a hard time ?? If its of any value, I can take a couple photos to explain.

Been working on this for ~6.5 hrs now ... any help will be appreciated.

EDIT: eventually found a picture of how the linkage connects, as it would connect (2) different ways ... fyi, if you're in the same situation -- the linkage goes horizontal, then Up (not down). It makes a difference, otherwise your shifting pattern is reversed.

dabeast727

thats wierd, i had teh exact same problem man. at exactly 35mph my truck would vibrate, the steering wheel would jolt up and down really fast and hte truck would vibrate. And when I put the clutch in, it goes away. I couldnt figure out how to get mine to stop so i jsut cleaned it out underneath really good, I think it was mud in the rims which i cleaned out and it just went away...

sgt_why

A lot of my vibration was because the CV joint connection the rear driveline to the axle was worn out and nearly busted.

I should have noticed it when backing up, it was very slack and then would "slam" when I let the clutch all the way out.

It finally just blew out on me a day or so later. so beware.

dabeast727

did you not a SYE/CV driveshaft?