Death Wobble - Help! (Solved)

[cheeseits52]

I’ve run two sets of tires on this new axle in the last 3 days, but still caused death wobble. I’ve tried rotating tires already.

I’m not putting the steering stabilizer on until the death wobble is solved, it will only mask the problem and not fix it.

I’ve been under the Jeep multiple times while the steering is rocked back and forth, there is no obvious movement on any of the steering. Placed my hand on all the components during this, felt no movement either.

I had an alignment too, and even with the correct toe, the problem persisted. That’s why I’m so confused. The tie rod has been adjusted so that neither end is beyond 3” per synergy’s instructions.

Sponsored

 

[Roky]

I’ve run two sets of tires on this new axle in the last 3 days, but still caused death wobble. I’ve tried rotating tires already.

I’m not putting the steering stabilizer on until the death wobble is solved, it will only mask the problem and not fix it.

I’ve been under the Jeep multiple times while the steering is rocked back and forth, there is no obvious movement on any of the steering. Placed my hand on all the components during this, felt no movement either.

I had an alignment too, and even with the correct toe, the problem persisted. That’s why I’m so confused. The tie rod has been adjusted so that neither end is beyond 3” per synergy’s instructions.

Well at this point , the dampener isn’t going to mask shit sounds like, why not put it on and see what happens……

 

[chadk77]

Are you running aftermarket wheels? and if so what is the bore size on the wheels?

 

[cheeseits52]

Are you running aftermarket wheels? and if so what is the bore size on the wheels?

Yes, but I’ve run those wheels for 3 years without issue. Bore 87.10mm I think.

 

[BUSHRVN]

You’ve still never said what the castor is at other than “in spec”. As others said, factory “in spec” is no good.

 

[chadk77]

Yes, but I’ve run those wheels for 3 years without issue. Bore 87.10mm I think.

The JL axle bore is 71.5MM. If those are 87.10MM I'd buy some 71.5 to 87.10 Hub Centric rings. My wheels were 78.1MM and allegedly lug centric. Every time I took the wheels/tires off and put them back on it rode different. Hub centric rings substantially smoothed it out. I could see that possibly contributing to death wobble. The rings are really cheap on Amazon.. Mine were $20 so worth a shot.

 

[VKSheridan]

I’m not putting the steering stabilizer on until the death wobble is solved, it will only mask the problem and not fix it.

I’ve been under the Jeep multiple times while the steering is rocked back and forth, there is no obvious movement on any of the steering. Placed my hand on all the components during this, felt no movement either.

The steering stabilizer doesn’t “mask” anything, it has a very specific job to do.

Think of the NEWTON’S CRADLE toy with the balls that clack endlessly. Put a moist sponge in between two of the balls and the toy gets real boring, real quick.

The same physics apply to wheels whose combined weight exceeds that of the steering components. Common sense says gravity wants the string on every Newton’s Cradle ball vertical yet gravity loses the argument with the drop of a single ball.

The same “ping pong” match is happened down below and your steering gear is akin to the string. Your left tire smacks the rod which smack turns the right tire until it sees sufficient resistance to smack back which smack turns the left tire. Because you are adding energy with motion, the smacking contest only gets worse until you stop adding energy by stopping.

Unless you plan on adding more and more weight to your steering linkages, anchors and gearbox to be closer to the weight of your wheels, you’re fighting physics.

The steering stabilizer is the “wet sponge” that absorbs the “turn smack” and reduces the impact shock that causes not just death wobble but increased wear on your ball joints. You want something to absorb the energy, not just give it more resistance as more resistance means more wear. More wear means even “weaker string” on that damned clacking ball toy….

Peace

 

[cheeseits52]

Caster is 5.66. My mistake on the wheels, wrong part number - the bore is 72.56.

I can try the steering stabilizer and see what happens.

 

[Wolfslash16]

The steering stabilizer doesn’t “mask” anything, it has a very specific job to do.

Think of the NEWTON’S CRADLE toy with the balls that clack endlessly. Put a moist sponge in between two of the balls and the toy gets real boring, real quick.

The same physics apply to wheels whose combined weight exceeds that of the steering components. Common sense says gravity wants the string on every Newton’s Cradle ball vertical yet gravity loses the argument with the drop of a single ball.

The same “ping pong” match is happened down below and your steering gear is akin to the string. Your left tire smacks the rod which smack turns the right tire until it sees sufficient resistance to smack back which smack turns the left tire. Because you are adding energy with motion, the smacking contest only gets worse until you stop adding energy by stopping.

Unless you plan on adding more and more weight to your steering linkages, anchors and gearbox to be closer to the weight of your wheels, you’re fighting physics.

The steering stabilizer is the “wet sponge” that absorbs the “turn smack” and reduces the impact shock that causes not just death wobble but increased wear on your ball joints. You want something to absorb the energy, not just give it more resistance as more resistance means more wear. More wear means even “weaker string” on that damned clacking ball toy….

Peace

This is the best way I've ever heard it put. Bravo sir!

 

[AnnDee4444]

So why don't other vehicles have steering dampers?

 

[Wolfslash16]

So why don't other vehicles have steering dampers?

Fair question. Most modern vehicles have rack and pinion style steering, which has far less mass and "unsprung" weight. Also by design they have less moving parts so they're not directly needed. However on Jeeps or any other vehicle with a solid front axle they do have steering dampeners. Even on some idler arm style steering cars they had steering dampeners.

TLDR; modern cars use objectively better designs that make them not needed/applicable.

 

[AnnDee4444]

Fair question. Most modern vehicles have rack and pinion style steering, which has far less mass and "unsprung" weight. Also by design they have less moving parts so they're not directly needed. However on Jeeps or any other vehicle with a solid front axle they do have steering dampeners. Even on some idler arm style steering cars they had steering dampeners.

TLDR; modern cars use objectively better designs that make them not needed/applicable.

But what is it about their design that makes the damper unnecessary?


I'm not an expert, but I don't think large trucks have a steering damper.

 

[Wolfslash16]

But what is it about their design that makes the damper unnecessary?


I'm not an expert, but I don't think large trucks have a steering damper.

Interesting observation. While I am not an engineer, I believe the main factor on the heavy duty application is that most of them are "behind the knuckle" steering, VS the Jeep and most truck "in front of the knuckle" design. It has to do with how the tires steer in relation to the steering geometry "steer center" and a few other things I don't fully understand. Maybe someone more qualified could chime in if they know what I am on going on about haha.

 

[Zandcwhite]

So why don't other vehicles have steering dampers?

Most don't have solid axles and the few HD trucks left have dana 60s or larger and ~30" street tires so the weight of the steering components is much closer to that of the tires and wheels?

 

[oldcjguy]

Caster is 5.66. My mistake on the wheels, wrong part number - the bore is 72.56.

I can try the steering stabilizer and see what happens.

You might want to try increasing the caster some. JL seems to like a little more caster to remain stable.

Sponsored