Join me on my Hunt for the Reason of the Dreaded Wobble

[Limited Ex]

Its weird, for as long as I have had my X and for all the things I have done to it, its ALWAYS driven spectacularly. Up until recently. I've gone through all the tire sizes, graduating bigger each time I bought new tires, and nothing bad has come about.

I had some 34" Trxxus MTs that I ran for awhile, they did great, until a buddy of mine at a truck shop called me. He brought to my attention a smoking deal on some 35" Pro Comp all terrains. Of course I bought them. Then things went bad.

As soon as I left the shop from getting them mounted, the whole vehicle started swaying terribly. I thought it could have been shocks, so I bought new Bilstein 5100s. Nothing. Long story short I eventually bought new tires, 35" Mud Kings. Bam, problem solved.

Well the last time I went wheeling, my steering box went south along with my alternator. I parked the X to fix all that and it stayed parked for a few months. A couple weeks ago I got it back on the road and the wobble is back in FULL force.

Here is what I have checked into and deemed Not The Cause:

Shocks
Alignment
CV joints
Ball joints
Wheels

What was replaced:
Coil springs no change
Leaf springs a lot of change
Bushings a little change
Motor Mounts no change
Tires a lot of change


I really really want to try new tires, but I don't have the cash. So I ordered a whole new bushing kit that should be here next week, I am going to check the ball joints, and a buddy of mine suggested checking the motor mounts since the wobbling only occurs under acceleration. It disappears once I let go of the gas.

The purpose of this post is mostly to document my case, as I have searched pretty decently on the topic. However, ideas and suggestions are of course welcome.

Let the hunt begin!

SWAY CONQUERED AS OF 5-22-08!

 

[BIGHVM]

I would start the reasoning with your wheels, Alloys can go out of round so easy, and cause these wobbles- jack up the car and mount a block of wood so it just touches the wheel at the outside edge, spin the wheel and if the bock of wood falls over- you have an out of round wheel!
Thats the first thing I would do mate- check both the fronts in this way.
Let us know what the outcome is


H

 

[unclemeat]

I am in on this one. Mine has the same problem. Superlift 5.5 with 33s BFG MT. When the tire pressure is low or different the wobble is worse. I have tried steering stabilizer, ball joints, Bilsteins, alienment, newer rear springs. These things have helped but not solved the problem. The best thing I have tried is tire pressure 35-psi.

I dont think it is motor mounts. I believe the reason that the wobble is worse under accerlation is because the weight is being transfered to the to the rear axle and unloading the front axle.

I am in the process of doing front sway bar busings, it seemed to have helped a little. I am conidering swaping a a 4-door front sway bar in to see it that helps.

I am stumped to, and this seems to be a common problem in lifted Gen. Explorers. I believe that there is not a single solution to the problem. I believe that all the suspects must be caught and repaired. i am running out of suspects.

 

[Albino 94LTD]

I eventually bought new tires, 35" Mud Kings. Bam, problem solved
My steering box went south. I parked the X to fix that and it stayed parked for a few months. A couple weeks ago I got it back on the road and the wobble is back in FULL force.

What kind of steering setup are you running? Drop pitman arm, Super runner or some other swingset type??

Double check TRE's and the drag link.

 

[Limited Ex]

Hmm, the wheels had not crossed my mind. I've had them for awhile now, and those are not too expensive to replace. I am going inspect those

Tire pressure really didn't do anything in my case. I dropped it to about 28psi and saw no change, so I am going to put it back to around 30-32. I really want those bushings to arrive so I can see if they do anything for it.

My steering is just a drop pitman arm. I do need to replace the tres and the drag link, as the boots on them are pretty well worn. I'd love to have a swingset setup, but for just a few $$ more I could have a solid axle

 

[Anime]

I've had the wobble, and was convinced it was the universal joints on the rear driveshaft, until new, balanced tires seemed to take care of most of the wobble. It can't be overstated that having all four of the wheels/tires balanced PERFECTLY to zero makes a HUGE difference, at least when the wobble is at speed. You might even want to watch them being balanced to be sure...too many shops just think its "close enough" and do a so-so job. I also cleaned up the driveshafts themselves, and taking off all the scale and rust that had accumulated on it seemed to make for an even smoother ride at speed, too.

Something else to keep in mind, especially with the first-gen's and the TTB, is alignment. Bushings and ball joints affect the positions of the wheels/tires, and if they're loose, worn, or wobbly, you'll get a wobble from that. Good shocks will dampen the wobble and vibration, but won't fix the problem.

Another thing to keep in mind, is due to the TTB design, especially stock or lifted with stock radius arms, when under heavy acceleration, the front end lifts up and so the front tires will be at a positive camber, due to the very tight travel arc of the stock design. This gives the first-gen a...unique feel when you really hit the gas, at least compared to other designs with more linear wheel travel. It's likely that with the big lugs of mud tires and maybe even all-terrains, you'll get some wobble/vibration from the front tires riding on the outer shoulder rather than the center.

 

[Limited Ex]

Okay good news, nothing has changed

Today I checked the cv joints and the ball joints, both were solid. I also rotated my tires and that did nothing. However, I am still not 100% convinced that it isn't the tires. If I knew someone local that had 35s on their Explorer, I would like to swap out tires so I could rule them out. Tomorrow the new bushing kit will arrive, so I should have that in by Saturday.

One other thing I am going to look into doing is getting another alignment done by a guy that I have used in the past. He goes a little more in depth, as he also does alignments on semi trucks. Of course he is more pricey than my other alignment guy whom I have always gone to.

 

[Limited Ex]

Though now I think about it, I have not had my tires balanced in a long time. Given, my Explorer has sat parked most of that time, I am still going to see about getting that done maybe tomorrow...

 

[Blacksheep Josh]

the one thing i've learned with having work done to my Explorer, is you get what you pay for... sure i might have a coupon for a 20$ front end alignment at tires plus, but it's never done right...

where as downtown, there's a guy that runs a hot rod shop, but also a regular auto shop to pay the bills.... it's about 60-70 dollars, but i can do 60 down the interstate, with no hands on the wheel (close though!) and it'll just glide perfectly straight.

if he does good work, go to him... and if he IS that good, he might be able to give you a clue to what it is... maybe he's seen it before in other suvs

 

[Limited Ex]

He does real good work, and as far as I know, thats ALL he does is alignments, and getting things fixed so everything is in alignment. I am going to pay him a visit if these bushings do not help.

 

[hunterdan]

I'm thinking that maybe having sat for so long that you may have developed a dead spot in the tire. How far and at what speeds have you driven? If possible I would try driving around to warm the tires up. They may have developed a flat spot that has not yet disappeared. I would also try to get them balanced. If your wheels are out of round as well, the balancer will show it.

Dan

 

[Albino 94LTD]

If you haven't yet, get the 'Road Force' balance from Discount tire. That will tell you if the tires are still round (or ever were round)

It makes all the difference in the world. I will never have any other method used on my tires!

 

[Limited Ex]

Oh I have driven it plenty to work out any dead spots, because that was one of my thoughts too. I've taken it down the highway and around town, and its not to the point that I feel unsafe driving it, since I know how to make it stop, but I can only imagine what cops or other drivers would think seeing the entire thing rocking left and right

Albino, what is this Road Force you speak of? Different method of balancing tires?

 

[Albino 94LTD]

They call it 'ride matching' on their web site; http://www.discounttire.com/dtcs/infoRideMatch.dos

Most tire places just spin them, this method simulated actual driving.

 

[mercious]

if the tires are out of balance all it'll do is at high speeds make the steering wheel shake a little not cause an extremely bad vibration... maybe try look at the tread and seeing if the tires are cupping real bad. also the alignment shouldnt make the vehicle shake violently like you say it is

i would check your rear drive shaft, have a driveline shop look at it and see if its bent or what not, that also could cause a vibration when you hit the gas. if it were me i wouldnt waste my money on an alignment, but having the tires road force would help a lot

 

[Limited Ex]

I called today to see about getting the Road Force balancing done, and it was going to end up being $64 After thinking some more about it, like mercious said, I would expect more vibration than swaying. And also, if I am coasting downhill, not pushing the gas, it rides fine. So I decided against it. For now anyhow.

What I did inspect today is the motor mounts, and there seemed to be some decent play in them when the gas pedal was pushed. So I ordered a set of them through Napa, they will be here in the morning. That would explain why it only happens when gas is applied. Though it does not shed light on why it drove fine before I had parked it a couple months ago....

On to the next experiment!

 

[Anime]

Maybe what you have isn't the "death wobble" but something else. Maybe giving a more detailed description of the symptoms would help? Does it just shake the entire rig under acceleration, or cause a wobble left and right, or cause the vehicle to want to go in another direction?

Since you said new tires fixed the previous occurance, if it's the same thing as before, maybe it IS the tires. At the very least you should get them rebalanced before spending any more money...hopefully you get free standard rebalancing from whereever you bought the tires. Worn engine mounts might give enough play to affect the driveshaft when it jerks and twists from the torque, so that could be it.

 

[Limited Ex]

Driving slow it is fine, but once I start accelerating normally, the whole vehicle starts to rock left and right. Bad. Once I let off the gas, it stops. Other than that, the X rides great. No vibrations or shimmies or anything, which makes me think that the tires are okay.

And its weird, as soon as I went with 35" ATs, the wobble happened. Swapped them out with 35" MTs, and it was fine. Until I parked it a few months ago. Now it is bad again

I realize that thinking its the engine mounts only explain why it wobbles under acceleration, but maybe it is a combination of bad mounts and worn bushings. So once I get the new mounts in, I will work on putting new bushings in. Then if that does nothing, I'll start working on the tires.

 

[Albino 94LTD]

Discount Tire told me the 'Road Force' balance was 'good for the life of the tire' so $64 isn't a bad deal at all. It's more than just balance, they can tell if the casing is bad and all kinds of things about the construction of the tire.

I wonder why you got a 'smokin deal'???? Bad batch??

 

[Limited Ex]

I got the deal on the Procomps because a lady had bought them for her lifted Tundra, but then turned around and decided that she wanted the look of a mud tire. So she left them at my buddys shop so they would get sold.

I'm still keeping that Road Force balancing on my list, I just figured right now I would throw money at something that I really believe could be causing issues.