Another source of death wobble not usually considered

bluejeep

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DW has a bunch of potential sources, and has been extensively covered prior to this posting. One source I've not seen discussed nearly as much is having axles parallel to one another.

This is my experience I just had yesterday.
Started getting death wobble at the usual 40'ish mph. I could accelerate past it and be fine. Then I noticed something new. At 60'ish or so if I turned slightly to the left (like to change lanes on the freeway) DW started up. Nothing like that happened when I turned to the right.

I checked all the usual suspects, everything seemed fine.
Then I remembered I had played with trying to reset the caster (was at 5 deg and wanted higher). During that process, which I was doing completely wrong by the way, I discovered I had the passenger side front axle 5/8" further forward, causing the axles to be non-parallel. I also remembered that while driving there was a need to turn the steering wheel just a bit to the right, against a slight tendency to pull to the left.

I discovered my error in moving the passenger end of the front axle forward, reset the axle parallel, and reset the caster (doing it correctly!) to 8.5'ish and it drives nicely now

Lesson learned - axles not being parallel should be something checked when correcting DW.
 
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I don't mean to minimize your experience, but I've never had a death wobble instance I thought I could throttle through. You sure that's what it was?

I've definitly had it before. If I can feel it coming on, I can either brake or accelerate and it goes away. I'm sure it has something to do with changing the resonant frequency of the wobble.
 
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There is no doubt in my mind that all of the alignment matters- To some degree or another.

Vibes come to mind- In a situation like you described- But I’m open to about anything being possible.
 
I don't mean to minimize your experience, but I've never had a death wobble instance I thought I could throttle through. You sure that's what it was?

Before it gets full on I can usually accelerate past 50 mph and it settles down
 
You absolutely can get past DW with more speed if you sense it early enough. Like way before its jerking the wheel out of your hand.
 
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I have had death wobble that only was triggered when turning to the right above 45 MPH. It was very odd.

I pulled the wheels and tires rotated them and serviced joints and re-torqued all the control arms and track bars so i'm not sure what solved it. Made too many changes at once to tell what the real cause was.
 
The one rig I had that experienced DW would usually do it after hitting a disturbance in the road, while at speed. The very first time was the most memorable, naturally, when it happened when I hit a particularly harsh expansion joint on a clover-leaf onramp, somewhere in Ohio, minutes after purchasing it and starting my 12 hour drive home. There was no gassing out of it.

It ended up disappearing when I installed a lift and new tires.
 
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I don't mean to minimize your experience, but I've never had a death wobble instance I thought I could throttle through. You sure that's what it was?

Yep, familiar with what it is, unfortunately
 
That’s not DW. That’s a shimmy. Tire balance. Check components too. D W you have to almost come to a full stop.

Sorry, what I have experienced was death wobble, not a shimmy. If you were there you can comment, otherwise move along
 
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DW has a bunch of potential sources, and has been extensively covered prior to this posting. One source I've not seen discussed nearly as much is having axles parallel to one another.

This is my experience I just had yesterday.
Started getting death wobble at the usual 40'ish mph. I could accelerate past it and be fine. Then I noticed something new. At 60'ish or so if I turned slightly to the left (like to change lanes on the freeway) DW started up. Nothing like that happened when I turned to the right.

I checked all the usual suspects, everything seemed fine.
Then I remembered I had played with trying to reset the caster (was at 5 deg and wanted higher). During that process, which I was doing completely wrong by the way, I discovered I had the passenger side front axle 5/8" further forward, causing the axles to be non-parallel. I also remembered that while driving there was a need to turn the steering wheel just a bit to the right, against a slight tendency to pull to the left.

I discovered my error in moving the passenger end of the front axle forward, reset the axle parallel, and reset the caster (doing it correctly!) to 8.5'ish and it drives nicely now

Lesson learned - axles not being parallel should be something checked when correcting DW.

The only point to take from this posting is the last sentence, that axles should be checked for being parallel if you have DW.
Unfortunately, some readers missed that line of thought and instead decided to contribute by saying what death wobble is and what it isn't, all the while not being in my LJ while it was occurring. So they completely missed out on contributing in a positive manner to a real issue for many of us.
Try not to lose the point of the original post if you go thru the rest of the replies. Have a great one!
 
Sorry, what I have experienced was death wobble, not a shimmy. If you were there you can comment, otherwise move along

I was not there, so I guess I can’t comment.

But since you were there, how about describe what happened instead of just saying you experienced death wobble.

I’ve personally never experience death wobble that did not require coming almost to a complete stop once it started - that is why everyone is questioning your description.
 
I was not there, so I guess I can’t comment.

But since you were there, how about describe what happened instead of just saying you experienced death wobble.

I’ve personally never experience death wobble that did not require coming almost to a complete stop once it started - that is why everyone is questioning your description.

not everyone is questioning my description, and others have commented they can 'power thru it if caught early enuf'. And I think we all know what death wobble is, but that's still off the point of my posting, which is "Check axles are parallel as well as other worn components and caster' if your front end is shaking, DW or not.
 
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And I think we all know what death wobble is,

I don't believe that's a safe assumption, given what I see on the FB jeep groups, but also simply based on the replies in this thread. There are different classes of vibrations & wobbles, and depending on what you've personally experienced it is easy to think you've encountered one when you actually encountered another. Several of us have lived through a thing you can't throttle out of, which is why we tried to drill into your specific experience, but you weren't super interested in that line of questioning.

It seems like you just wanted to tell us about the importance of axle alignment (is this what the shops call "thrust angle?"), which I don't think anyone here would disagree with in the slightest. It's definitely not talked about much, but with as many people running adjustable arms all the way around, I'm sure it's actually a much bigger thing than people realize. I know I've never measured mine. ¯\_(ツ)_/¯