Bad Oscillations at 65 mph

[DailyMoparGuy]

Let me start this by saying it is NOT D**th W***le. I have also checked the torque on everything and no issues there, everything was to spec.

A couple of months ago, I was dealing with some steering wheel vibrations after getting my new 37” Mickey Thompson tires (55-65mph). I had them balanced multiple times and the vibration seemingly went away. It drove great down to PA and back about a month ago.

Edit: RSI Smartcap added to truck after PA trip. I don’t think it’s causing this though. Also, I’m on stock ball joints and the truck has 57k miles on it. About 37k miles were on 35s. Wouldn’t surprise me if the ball joints were shot.

Fast forward to last weekend’s trip to Vermont, the steering wheel shake is back at 55 mph but pretty much disappears after driving for a little while (not sure what to make of that).

I also noticed a pretty bad oscillation/bounce at 65 mph. Here’s the odd part - the oscillation at 65 mph kinda shakes the entire truck, but the steering wheel doesn’t move at all. The oscillation movement is rhythmic, not constant…6 seconds of oscillation, 6 seconds of good ride quality, rinse and repeat for 4 hours of driving lol.

So my best bet is my alignment at this point. I also plan to take off the Fox 2.0 ATS stabilizer and see if the shake goes away. While I was under the truck I also noticed some signs of diff/axle leakage. It looks too fresh to be the same sludge from 20k+ miles ago when it first got warranty repaired (dealer to check on this at my next appointment). Could that be related to this rhythmic oscillation at 65 mph?

I know it’s a very wordy post lol. I just wanted to include everything I observed. Let me know if there’s a different way you would approach this.

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[ErylFlynn]

Check the tire balance. I have had issues with vibration like that caused by tires being out of balance.

 

[RkellysJeep]

Ever changed the wheel bearings? Every car I’ve ever had that shook that ended up being the problem.

 

[Reddog]

Let me start this by saying it is NOT D**th W***le. I have also checked the torque on everything and no issues there, everything was to spec.

A couple of months ago, I was dealing with some steering wheel vibrations after getting my new 37” Mickey Thompson tires (55-65mph). I had them balanced multiple times and the vibration seemingly went away. It drove great down to PA and back about a month ago.

Edit: RSI Smartcap added to truck after PA trip. I don’t think it’s causing this though. Also, I’m on stock ball joints and the truck has 57k miles on it. About 37k miles were on 35s. Wouldn’t surprise me if the ball joints were shot.

Fast forward to last weekend’s trip to Vermont, the steering wheel shake is back at 55 mph but pretty much disappears after driving for a little while (not sure what to make of that).

I also noticed a pretty bad oscillation/bounce at 65 mph. Here’s the odd part - the oscillation at 65 mph kinda shakes the entire truck, but the steering wheel doesn’t move at all. The oscillation movement is rhythmic, not constant…6 seconds of oscillation, 6 seconds of good ride quality, rinse and repeat for 4 hours of driving lol.

So my best bet is my alignment at this point. I also plan to take off the Fox 2.0 ATS stabilizer and see if the shake goes away. While I was under the truck I also noticed some signs of diff/axle leakage. It looks too fresh to be the same sludge from 20k+ miles ago when it first got warranty repaired (dealer to check on this at my next appointment). Could that be related to this rhythmic oscillation at 65 mph?

I know it’s a very wordy post lol. I just wanted to include everything I observed. Let me know if there’s a different way you would approach this.

Interesting issue. I get my 37's balanced and rotated every 8K miles. I have AEV wheels and twice I have had the glue on weights come off after balancing. Never had the issue before on any vehicle but had it happen twice this past year. So if your Jeep drives nice for a while after balancing and then suddenly doesn't, wheel weights may be the cause. Otherwise, check the wheel bearings although I would think you would hear a rumble if that was the issue.
Good luck to you.

 

[DailyMoparGuy]

Interesting issue. I get my 37's balanced and rotated every 8K miles. I have AEV wheels and twice I have had the glue on weights come off after balancing. Never had the issue before on any vehicle but had it happen twice this past year. So if your Jeep drives nice for a while after balancing and then suddenly doesn't, wheel weights may be the cause. Otherwise, check the wheel bearings although I would think you would hear a rumble if that was the issue.
Good luck to you.

Thanks for the input. The weights actually did fall off once before. That definitely could be the culprit.

 

[DankjeeP]

If it is not affecting the steering, maybe it is something going on with the rear axle. Do the tire balance then if still wonky front rear swap maybe. Good luck.

 

[ShadowsPapa]

Ever changed the wheel bearings? Every car I’ve ever had that shook that ended up being the problem.

Wheel bearings don't cause that sort of issue. I'd bet that the REAL cause was resolved when the wheel bearings were replaced. These don't have car type wheel bearings in any case.........

It looks too fresh to be the same sludge from 20k+ miles ago when it first got warranty repaired (dealer to check on this at my next appointment). Could that be related to this rhythmic oscillation at 65 mph?

VERY unlikely - although a shake caused by a tire or wheel issue can wear on bearings and seals. So it's the victim, not the cause, but then these have had some leak issues anyway. So, I'd consider that leak a distinct issue by itself.

Two things come to mind -
I had a wheel that was out of whack. It didn't have the sort of runout that shops, or even myself, would check for - meaning it wasn't lateral. The dial indicator places on the outer rim ran steady. The wheel was egg shaped, and it created almost exactly the sort of issues you describe. The whole damn car shook bad, but you couldn't pinpoint where it was coming from. I rotated tires, tire shops checked balance over and over, an axle shop said it was fine, they found no issues.
The problem was minor at about 55, then it came in around 65 mph and I could "drive through it" if I ignored the fact I might find the car self-destructing before I hit 75 and it smoothed out. In town it was perfect.
Granted, much much smaller tires so the mph doesn't line up quite right between your big tires and my Eagle's 15" tires.
Another area to look at - DRIVE SHAFT.
If you have a lift and a shaft with a single cardan joint at one end only, that joint needs to run very straight, all but 0 degrees.

 

[DailyMoparGuy]

Wheel bearings don't cause that sort of issue. I'd bet that the REAL cause was resolved when the wheel bearings were replaced. These don't have car type wheel bearings in any case.........


VERY unlikely - although a shake caused by a tire or wheel issue can wear on bearings and seals. So it's the victim, not the cause, but then these have had some leak issues anyway. So, I'd consider that leak a distinct issue by itself.

Two things come to mind -
I had a wheel that was out of whack. It didn't have the sort of runout that shops, or even myself, would check for - meaning it wasn't lateral. The dial indicator places on the outer rim ran steady. The wheel was egg shaped, and it created almost exactly the sort of issues you describe. The whole damn car shook bad, but you couldn't pinpoint where it was coming from. I rotated tires, tire shops checked balance over and over, an axle shop said it was fine, they found no issues.
The problem was minor at about 55, then it came in around 65 mph and I could "drive through it" if I ignored the fact I might find the car self-destructing before I hit 75 and it smoothed out. In town it was perfect.
Granted, much much smaller tires so the mph doesn't line up quite right between your big tires and my Eagle's 15" tires.
Another area to look at - DRIVE SHAFT.
If you have a lift and a shaft with a single cardan joint at one end only, that joint needs to run very straight, all but 0 degrees.

Lots of good info here, thanks. And yup, the truck smooths out some towards 75 mph just like what you experienced before.

The drive shaft makes sense too. I never installed the carrier bearing spacer that I bought like a year ago. Hell, I don’t even know where I stored it lol.

Lots of things to comb through I suppose. I’ll figure it out eventually and report back.

 

[TheSolarWizard]

Try driving it in 4wd at 55 (straight only) and see if the vibration changes. 2-3 miles only.

 

[ShadowsPapa]

Try driving it in 4wd at 55 (straight only) and see if the vibration changes. 2-3 miles only.

There's an idea. Wouldn't work with my JT, but with his, worth a shot.

 

[DailyMoparGuy]

Try driving it in 4wd at 55 (straight only) and see if the vibration changes. 2-3 miles only.

I will definitely give that a shot. Thanks

 

[Stan H]

Let me start this by saying it is NOT D**th W***le. I have also checked the torque on everything and no issues there, everything was to spec.

A couple of months ago, I was dealing with some steering wheel vibrations after getting my new 37” Mickey Thompson tires (55-65mph). I had them balanced multiple times and the vibration seemingly went away. It drove great down to PA and back about a month ago.

Edit: RSI Smartcap added to truck after PA trip. I don’t think it’s causing this though. Also, I’m on stock ball joints and the truck has 57k miles on it. About 37k miles were on 35s. Wouldn’t surprise me if the ball joints were shot.

Fast forward to last weekend’s trip to Vermont, the steering wheel shake is back at 55 mph but pretty much disappears after driving for a little while (not sure what to make of that).

I also noticed a pretty bad oscillation/bounce at 65 mph. Here’s the odd part - the oscillation at 65 mph kinda shakes the entire truck, but the steering wheel doesn’t move at all. The oscillation movement is rhythmic, not constant…6 seconds of oscillation, 6 seconds of good ride quality, rinse and repeat for 4 hours of driving lol.

So my best bet is my alignment at this point. I also plan to take off the Fox 2.0 ATS stabilizer and see if the shake goes away. While I was under the truck I also noticed some signs of diff/axle leakage. It looks too fresh to be the same sludge from 20k+ miles ago when it first got warranty repaired (dealer to check on this at my next appointment). Could that be related to this rhythmic oscillation at 65 mph?

I know it’s a very wordy post lol. I just wanted to include everything I observed. Let me know if there’s a different way you would approach this.

I had this very issue , was a bent rim.. happened the first with stock rims then i accidentally did a bad drop with a new steel rim thought everything was ok. Until it got rotated to the front that is when I knew exactly what it was confirmed by jacking up front rotating tire.

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