Advice on death wobble. And caster.

[cosmokenney]

Hi all, I am seeking advice on how to proceed from where the jeep is at now. I have a '19 2 door Rubicon.
After installing my 2" lift and 37s, I got a little shimmy. Mostly just some rapid feedback in the steering wheel.

So, I decided to put install Metal Cloak tie rod and drag link. That actually made things worse. Especially when on pavement, and when aired down, I get a full on death wobble after hitting bumps. I have to slow down to about 15MPH to get it to stop.

To fight that I figured with 41K miles on the jeep I would install a set of Teraflex Ball Joints to see if that helped. Nope. If I am aired down to about 18 psi repeated bumps will send it into a tizzy.

Before you ask why I am riding on pavement when aired down -- its because I live two or three miles from the national forest and spend a lot of time there. So I usually just air down in the garage. And air back up in the garage when I need to drive the jeep on pavement for more than 5 minutes.

I would like to fix the problem so I am not causing excessive wear and tear on the rest of the steering and suspension.

Note that the lift is about 6 months old so all the joints should still be pretty tight. I have full adjustable everything in the suspension.

Attached is the alignment after doing my lift. And a picture I took earlier this week of the angle at the front diff, after installing the tie rod, drag link and ball joints.

According to my alignment I am at 7 degrees caster. And that pretty much jives with what the angle finder shows. Though according to my calculations based on the angle finder I am at 7.6 degrees.

Should I try to remove some of the caster to get to more like 6 degrees? Beyond adjusting caster, I don't know what else to look at since everything in the suspension and steering are so new.

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[Whaler27]

There are many threads on death wobble diagnosis and cure.

It’s worth using the search engine and doing some reading, but I’d start by getting under the jeep and confirming that everything really is tight. A six month old lift may well be tight if everything was properly retorqued after putting some miles on it, but I would not just assume that. You have to check. In my experience a loose/sloppy/worn component is almost always the primary source of the DW problem.

On a somewhat related note, the Steer Smarts Yeti is a magical piece of hardware.

 

[Old Jeeper]

Hi all, I am seeking advice on how to proceed from where the jeep is at now. I have a '19 2 door Rubicon.
After installing my 2" lift and 37s, I got a little shimmy. Mostly just some rapid feedback in the steering wheel.

So, I decided to put install Metal Cloak tie rod and drag link. That actually made things worse. Especially when on pavement, and when aired down, I get a full on death wobble after hitting bumps. I have to slow down to about 15MPH to get it to stop.

To fight that I figured with 41K miles on the jeep I would install a set of Teraflex Ball Joints to see if that helped. Nope. If I am aired down to about 18 psi repeated bumps will send it into a tizzy.

Before you ask why I am riding on pavement when aired down -- its because I live two or three miles from the national forest and spend a lot of time there. So I usually just air down in the garage. And air back up in the garage when I need to drive the jeep on pavement for more than 5 minutes.

I would like to fix the problem so I am not causing excessive wear and tear on the rest of the steering and suspension.

Note that the lift is about 6 months old so all the joints should still be pretty tight. I have full adjustable everything in the suspension.

Attached is the alignment after doing my lift. And a picture I took earlier this week of the angle at the front diff, after installing the tie rod, drag link and ball joints.

According to my alignment I am at 7 degrees caster. And that pretty much jives with what the angle finder shows. Though according to my calculations based on the angle finder I am at 7.6 degrees.

Should I try to remove some of the caster to get to more like 6 degrees? Beyond adjusting caster, I don't know what else to look at since everything in the suspension and steering are so new.

If you are at 7.6 on caster you really need to dial it back.

When you air down it increases the length of your wheelbase. Adding taller tires increases the wheelbase and then airing down, no doubt you have 7.6 which is way to much. I would dial in a 6.5 and see what that does for you.

 

[cosmokenney]

There are many threads on death wobble diagnosis and cure.

It’s worth using the search engine and doing some reading, but I’d start by getting under the jeep and confirming that everything really is tight. A six month old lift may well be tight if everything was properly retorqued after putting some miles on it, but I would not just assume that. You have to check. In my experience a loose/sloppy/worn component is almost always the primary source of the DW problem.

On a somewhat related note, the Steer Smarts Yeti is a magical piece of hardware.

Thanks. I've read some threads on death wobble. Most say to increase the caster or replace the ball joints or replace the stock Tie Rod and Drag Link. All of which I've done.
BTW, when I look at Steer Smarts website they have many items with the name Yeti: Drag Link; Track Bars; ...
Which "Yeti" are you referring to?

 

[Philly_]

I run very low caster on my two door with a 2.5” MC suspension and 35’s. Something like 4.5 I think, but it’s close to stock Rubicon specs and handles like it so it was good for me.

Check your frame side front track bar bracket for wallowing. This seems to be the number one problem area (from what I’ve read on the forums) for death wobble and vibration on the JL’s. The stock torque specs are way too low, so I go off what Steer Smart recommends with their kits, which I don’t have off hand but is significantly higher. Fixed a lot of my issues.

Also the Metalcloak track bar may be moving around on the bolt if you’re reusing stock hardware… I saw another forum member switch all of their metric bolts to imperial equivalents and it was a tighter fit through the bushings in their Metalcloak track bar and solved their problems.

 

[Whaler27]

Sorry. The Yeti Track bar Is what I was referring to. You probably saw this video linked on one of the DW threads, but just in case, I’ll link it again below.

DW can be super frustrating and vexing — like trying to track down an intermittent short in an electrical system, but it can always be fixed.

Yeti

 

[Fuel Fire Desire]

7.6° is too much caster for a factory axle housing. Anything beyond 6° gives you a pinion angle pointing towards the ground. It can be done on a custom or aftermarket axle, but not on factory without having a very awkward driveshaft angle. That said, it shouldn’t be a cause for DW.

I run 6°, and am very pleased with steering feel (stiffer), faster return to center, and no wandering like the JL did since new.

 

[silverooby]

Installing a track bar support at the steering box end is what fixed my wobble. There seems to be enough flex at that end of the bar to set off the wobble, particularly with larger tires. Checking for tightness with your hands cannot apply the forces that set off wobble. Everything needs to be tight, but flex can still be the culprit as was the case with my trackbar.

 

[cosmokenney]

I have already replaced the stock suspension (new adjustable front/rear track bars and upper/lower control arms) and steering (drag link, tie rod) and ball joints. I guess I'll start looking at the various reinforcement brackets. And I'll retorque everything.
I also suspect the toe could be out of adjustment. So I'll look into going 1/8" toe-in. And I'll dial back that caster to 6-ish.

 

[cosmokenney]

I have already replaced the stock suspension (new adjustable front/rear track bars and upper/lower control arms) and steering (drag link, tie rod) and ball joints. I guess I'll start looking at the various reinforcement brackets. And I'll retorque everything.
I also suspect the toe could be out of adjustment. So I'll look into going 1/8" toe-in. And I'll dial back that caster to 6-ish.

Finally got around to setting my toe and caster. Used a pair of 24" angle irons clamped to my rotors. Toe in is at 1/8" difference between the front and back of the angle irons. And caster is at 6-ish degrees.
BUT, while I was in there I found all 4 upper control arm jam nuts finger tight. Literally loosened them with my fingers.

And, since my last post on this thread I installed a Rusty's trackbar bracket.

Still getting a slight wobble at 55+ when aired down to 17 PSI. But I haven't tried with them aired back up to normal.

 

[Garrett19]

You have a very similar set up to my jeep and actually pretty close in miles as of your first post. I have the synergy track bar brace up front that also grabs the steering box. That made a big difference on the feeling and overall ability to track strait without a lot of steering input. Also like someone else mentioned, MetalCloak track bars have larger holes than the stock parts and hardware so I have switched to 9/16" bolts on both side of the bar for a tighter fit. I had a slight wobble on my jeep at 55mph but not faster or slower and that ended up just being a tire balance issue so if you haven't tried that yet it, might be an easy fix.

I think my caster is at 6 degrees as well, hope that helps.

 

[AVGeek99]

You have a very similar set up to my jeep and actually pretty close in miles as of your first post. I have the synergy track bar brace up front that also grabs the steering box. That made a big difference on the feeling and overall ability to track strait without a lot of steering input. Also like someone else mentioned, MetalCloak track bars have larger holes than the stock parts and hardware so I have switched to 9/16" bolts on both side of the bar for a tighter fit. I had a slight wobble on my jeep at 55mph but not faster or slower and that ended up just being a tire balance issue so if you haven't tried that yet it, might be an easy fix.

I think my caster is at 6 degrees as well, hope that helps.

I've been working through some shimmy and DW issues of my own that started happening immediately after having a MC 3.5 GC lift installed. Prior to the lift everything was fine with no hint of any shimmy or DW.

I'll be installing Steersmarts Yeti tie rod and drag link in a few weeks, but I want to correct any other issues first. Do you know the exact size and length of the bolts you used for the trackbar? Grade 8 I assume? Do the larger bolts fit the mounting holes or did you have to drill them out?

 

[Garrett19]

Another member made a thread about it here but I will say that I used fine thread just because stock bolts were also fine thread, I'm sure there is no real advantage in thread pitch in this application. There is no need to drill anything out for the 9/16" bolts.

 

[AVGeek99]

Another member made a thread about it here but I will say that I used fine thread just because stock bolts were also fine thread, I'm sure there is no real advantage in thread pitch in this application. There is no need to drill anything out for the 9/16" bolts.

I have a thread going about adjusting caster and my own quest of fixing my DW. On that thread someone pointed me to SteerSmarts. They sell a 9/16" bolt kit for the trackbar. I have it on order and it should arrive on Friday. I'll install on Saturday and hopefully it will resolve my problem.

 

[AnnDee4444]

You may be able to mask it with different alignment settings, but this is not an alignment problem.

For me the answer was a Metalcloak track bar brace. I actually didn't have it fully installed at first, missing the two lower bolts that required drilling the frame (I was waiting on a drill bit). With it partially installed there was very little difference, which is similar to what I would expect from the other braces that just bolt to the steering box. After adding the two lower bolts, everything became much more rigid. This is with the stock track bar & hardware.

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