Wobbling when stopping and accelerating

[ewack3]

I have searched the forum trying to find a similar case, but haven't stumbled on anything yet.

My '98 V8 AWD EB explorer (173,000 miles) has been having vibration problems at high speeds (70 mph) for quite awhile. There is a wobble that you can feel from side to side when slowing down to a stop and when accelerating. This goes with the roll of the tires. There is also a whoop noise, not quite grinding that sounds like it's with the roll of the wheels (leading me to have the bearings checked by a number of people).

I have had the wheels indexed, balanced, rotated, and inspected by a few different shops. No one seems to know why it's doing what it is, but here's the info I have so far.

The shocks are a few years old, prolly have 40k to 50k miles on them, they are air shocks to match the air ride system. Sway bar bushing links were recently changed. Bearings have been inspected and said to be 'ok'. The rack and pinion is seeping, but not bad enough to replace (according to the shops). Tires have about 35k to 40k on them and are very slightly cupped. There are new rotors and pads on the front brakes.

Please let me know if you need more info, any help is very welcome.

Thanks!

 

[my98nnj]

It has to be a wheel and tire issue. The cupping isn't good either, it indicates possible alignment problems or worn or lose suspension components.
The wobble could very well be a bad belt in a tire. Sometimes not noticable when you balance a tire. But under a load it shows up. I just replaced a Goodyear Comfortread on my Nissan Maxima do to that very symptom. Had a wobble in the steering wheel at slow speeds. Took me a while to pin point which tire it was, once it was replaced everything became nice and smooth once again.

 

[ewack3]

Thanks for the feedback, I really appreciate it. I've had it aligned recently and didn't notice it helping at all. I haven't liked these tires much anyways (goodyear RT/S). I think I may take it in for new tires since 2 shops haven't noticed anything wrong with the suspension.

I noticed there is a 5th shock in the back for stability. Would that make any difference if changed out? Being it has so many miles and I doubt that it was ever changed.

As far as you saying a "wheel" issue...did you mean like having a bent rim or something else? - I'll have them all checked next week anyways, thanks for the reminder.

Would the bushings cause a constant vibration? They don't look terrible, but I'm sure a few could be changed out.

 

[ewack3]

I wanted to follow up on this thread...just in case someone finds it later.

I had a tire shop look it over. They ran it while lifted and found that 3 of the 4 tires were very out of shape, possibly separating. I replaced all those and all the noises and wobbling have stopped. I had Goodyear Wrangler RT/S tires on it (this was my second set) both sets went early...this last set was at about 18k when the noises started.

I also had the "5th shock" replaced aka the rear stabilizer and things seem to be a bit tighter in the handling but not overwhelmingly. It's never been changed and at 173,000 and leaking, I thought it would make more of a difference.

Thank for again for your advice on looking more into the tires, it solved my problem!