Death wobble with the new 37" Cooper STT Pros

Ozon8r

Ozon8r

Member
Appreciate some sage advice from those with experience running 37"+ tires.

After reading the reviews here, I decided to upgrade to 37/13.5R17 cooper STT Pros over the same size Nitto Trail Grapplers! Man I love the look of theses tires on my '14 jku rubi (37k miles). While not my DD, I do enjoy driving it with top and doors off around town weather permitting.

But now after 100 miles of use, I experience a steering shimmy which becomes extremely violent and loud between 40-50 mph. I have to bring the jeep to a complete stop to kill the shake. If I accelerate thru 50mph without spending too much time btwn 40-50mph, the shimmy diminishes as speed increases and I just hear an oscillating noise from the tires. The tires track true with no pull and there are no visible issues. I'm running 4.5" lift with drag link in stock position, but don't experience any bump steer issues.

Discount Tire attempted to road force balance twice since install and no improvement. I had a similar experience with Duratracs which was resolved by rebalancing.

I am reasonably sure that this is not true death wobble based on performing troubleshooting techniques posted in this forum. Front end is tight and torqued and bushings look healthy. But the jeep feels like the bolts are going to rattle loose and come apart at the seams when it starts shaking.

Should I expect that a tire this size cannot be balanced and I will just accept the drive characteristics with 37s? Should I ask for a different set of tires? Thanks
 
I just experienced this with my shitty rubicon express lift, to me, death wobble screams trackbar. Make sure your trackbar is torqued
 
Ozon8r said:
Appreciate some sage advice from those with experience running 37"+ tires.

After reading the reviews here, I decided to upgrade to 37/13.5R17 cooper STT Pros over the same size Nitto Trail Grapplers! Man I love the look of theses tires on my '14 jku rubi (37k miles). While not my DD, I do enjoy driving it with top and doors off around town weather permitting.

But now after 100 miles of use, I experience a steering shimmy which becomes extremely violent and loud between 40-50 mph. I have to bring the jeep to a complete stop to kill the shake. If I accelerate thru 50mph without spending too much time btwn 40-50mph, the shimmy diminishes as speed increases and I just hear an oscillating noise from the tires. The tires track true with no pull and there are no visible issues. I'm running 4.5" lift with drag link in stock position, but don't experience any bump steer issues.

Discount Tire attempted to road force balance twice since install and no improvement. I had a similar experience with Duratracs which was resolved by rebalancing.

I am reasonably sure that this is not true death wobble based on performing troubleshooting techniques posted in this forum. Front end is tight and torqued and bushings look healthy. But the jeep feels like the bolts are going to rattle loose and come apart at the seams when it starts shaking.

Should I expect that a tire this size cannot be balanced and I will just accept the drive characteristics with 37s? Should I ask for a different set of tires? Thanks
Click to expand...

First off, a really bad shimmy like you've just described is NOT death wobble. Second, a speed related shimmy is almost always a tire balancing issue. If you are running steel wheels, it could be that one is out of round. Have you tried rotating your tires to see if the shimmy changes in feel?
 
wayoflife said:
First off, a really bad shimmy like you've just described is NOT death wobble. Second, a speed related shimmy is almost always a tire balancing issue. If you are running steel wheels, it could be that one is out of round. Have you tried rotating your tires to see if the shimmy changes in feel?
Click to expand...

Good point on the wheels being out of round, I'll rotate fronts to rears, rears to front and report back. Appreciate the quick replies.
 
Quick update. Rotating fronts to rear and rears to front resolved the issue. Very much appreciate the advice. Need to buy some new wheels I guess.
 
Ozon8r said:
Quick update. Rotating fronts to rear and rears to front resolved the issue. Very much appreciate the advice. Need to buy some new wheels I guess.
Click to expand...

Make sure you get your tires rebalanced then. Try to find a place that does road force balancing
 
you might go back to discount and have them dis-mount the rears and check the wheels only for balance. they've done that for me in the past when I had to check a wheel only for damage - this may also depend on the Discount Tire.

personally I wouldn't want a wheel that out of round on the rear since it's the main driving force, not sure if it could cause damage to the flange or internals but if it was causing that much shake in the front I'd have them checked.
 
jeeeep said:
you might go back to discount and have them dis-mount the rears and check the wheels only for balance. they've done that for me in the past when I had to check a wheel only for damage - this may also depend on the Discount Tire.

personally I wouldn't want a wheel that out of round on the rear since it's the main driving force, not sure if it could cause damage to the flange or internals but if it was causing that much shake in the front I'd have them checked.
Click to expand...

Great point. ^^^^This issue may be an excuse to convince my wife the jeep needs bead locks for the safety of our children [emoji3].
 
Balancing Your Beadlocks

You'd probably want to check with whoever balances your wheels/tires to make sure they will do beadlocks. I was at my local (Albuquerque) Discount tire store last week and the manager told me that their corporate policy is that they will (no longer) mount or balance beadlocks. Said they used to do almost anything (like beadlocks and the 19.5 and 22.5 motorhome tires) but, with liability, corporate is cutting back on what they can do. Even if your shop will currently do beadlocks, there is no guarantee that they will do it later on.
 
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