My son has a 2001 Explorer Sport Trac 4X4. It was pulling slightly to the right and a little vibration from out of balance tires so we took it to be aligned and have the wheels balanced. . Found out the steering rack was bad. Replaced the rack, and drove it back to the alignment shop. They aligned it. It rode fine up to about 40 mph them it began a violent wobble. Took it back and he said he thought the rack must be bad but our mechanic can't find anything wrong with the rack. He did find a loose bolt on the upper control arm and tightened it and thought that fixed it. The test drive was fine, but when we picked it up from him it began to wobble violently again on the way home. Any ideas on what to check? Would a bad alignment cause this? It has sightly over sized tires, lift, and 1 1/2" wheel spacers but it was fine like that prior to the work we've had done.

not sure but it sounds like you need to take the mechanic for a ride so he can experience what you are.

do you have a set of normal size wheels without spacers he could borrow off of your truck for a day to see if that changes it ?

lots of places short staffed right now don't have the time for the a longer road test to get up to the speeds you would on the way home.

I had a Chevy PU wobble bad at 60+ mph and it was a tire separating. It would stop and smooth out about 80mph. Here I would say it was a five lb block of ice stuck to the inside of a wheel.

He has had it do it while he's driving it. And these tires have been on it for years, since before we bought it 3 years ago.

ok , when your stumped , you have to change something , if you have spare wheeles and tires or can borrow them off your truck , it either does it after the change and you know it isn't wheels and tires or it stops and you can start looking at what wheels and tires could be causing it.

if he can borrow your wheels and tires then it is a cheap test all he need is a jack and a 4way and he can do it himself.

First things first..the upper control arm bolts on that thing are an eccentric bolt, and control camber and caster settings. If whoever did the alignment left one of them loose, I'd almost guarantee that the alignment is out of whack. At the very least, it needs to be rechecked.

Once the alignment is loose, something else will need to be fixed. A wonky alignment will cause a pull, but not a wobble or shake. Off hand, I'd say its likey a tire that's got a seperated belt. But it could be a lot of things. If it's not the tires, your mechanic may be able to put it up on a lift and put it in gear and "drive" it up to speed and look for where the wobble is coming from.

The wobble is in the steering wheel it moves rapidly back and forth 3-5" before you have to hit the brakes or loose control of the truck. Tires were rotated front to back and balanced and didn't effect the wobble.

If it's in the steering wheel, it could possibly be in the four wheel drive system. Something like a front axle coming apart.

Quit spoiling the kid. A death wobble teaches kids to slow down on country roads…..

Could be any of the front end linkages. The older ford trucks had a huge problem with the center link going bad, and other bushings going bad which caused the same thing as yours. Last one I repaired it took me forever to find the bad bushing then wound up replacing all of them just to make sure.

Like said, if a control arm was left loose it will most certainly need to be re aligned.

F.ix O.r R.epair D.aily

Well, it was fine before it was aligned. We drove it 40 miles from the shop where the steering rack was replaced to the alignment shop, all it had was a slight tire out of balance vibration. They aligned it, apparently leaving the upper control arm bolt loose, and it started this wobble thing. Back at the mechanic he tightened the bolt but the wobble remains. All the bushings and joints seem to be tight, no play in them.

I know it need to be realigned but will that cause the wobble? It's causing up a lot of gas money delivering 40 miles from one shop to the other. It goes straight down the road at lower speeds.

Has anyone checked to see if all lugnuts are tight? Adapter to hub and wheel to adapter? I'm not a fan of adapters...

Yes. They were all torqued down. It can't be that simple with my vechiles.

the upper control arm on that also controls the caster , too much negative caster and it wobbles like a shopping cart front wheel when you got fast that could easily = death wobble

here is what the control arm looks like and how it is replaced

if you want to skip to the control arm explanation skip to 16 minutes in

That is the info I was looking for. Hopefully if we can get back to the alignment shop and get that fixed it'll stop the wobble.

from the looks of it loosen the 2 bolts that hold the control arm on so that it can slide and then the adjuster on the end is probably way out bring that back in to give yourself some positive castor then tighten the two bolts down and try driving to the alignment shop.

the best way i have found to think of caster is a chopper motorcycle has a LOT of positive caster you can't even muscle the handle bars , you lean to turn the wheel always wants to return to strait when you have a little positive castor

a shopping cart front wheel has negative caster so that it wants to go what ever way the cart is turned it always follows and doesn't fight to go strait but like a shopping cart running through the store they wobble at higher speeds

South Main Auto rocks. Wish we had an independent mechanic like him around here.

In this situation I would ask myself, " what would Coonman do????" That will be your answer.