Incurable Death Wobble Need Help

[Wrz]

Well ive been building this beauty for over a year now, I have alot of blood,sweat, and i stopped keeping track of all the money ive spent. Shes finally at the point now where shes ready to be driven daily, but i cannot get ride of this death wobble. 

 

Keep in mind ive never been able to get this jeep over 40 since owning. Ive had two alignments done within the last 2 weeks and nothing i throw at it seems to help.  While getting up to some speed as soon as i hit a small bump, or a pebble at that the truck starts to shake and the wobble starts. The wobble is too bad to accelerate through ( too risky to try), and wobbles more while holding on and trying to slow down as fast as possible.  

 

specs- 1990 lwb, 4.0, auto, 4x4,  approximately 4.5 lift  

 

New parts installed since the build started

 

Front Hubs ( auto zone )

Front u joints ( spicer )

Ball Joints ( spicer )

Ruggid ridge Steering

Used zj v8 Sway bar ( Poly Bushings )

Sway Bar Links ( Fixed Length )

Stock upper control arms

Beefier Fixed Lower Control arms

rough County Stabilizer

Rough Country Trackbar ( adjustable )

New Cooper 265 75 16 AT3 tires

 

 

Installed within the last week ( all New )

Durango steering box 

Steering box stiffener plate 

M.O.R.E box brace

New Steering shaft

 

Everything under the jeep seems to be nice and tight with no play at all. At this point the comanche is turning into a drive way ornament. I'm just about out of funds for it and am stumped

Ive been reading through several forums and cannot pin point it. 

 

Tires were all speed balanced as well

 

Here are the specs i got from my mechanic

 

 

 

 

Any help would be highly appreciated, Tomorrow ill try and see if i can get a video of the front while it starts to wobble, and will take some pictures of the front end if it will help 

[Strokermjcomanche]

Some of my friends have been known to put golf balls in their tires to help balance them out . Or maybe try to engineer a way to put a second steering stabilizer on .

[Wrz]

Some of my friends have been known to put golf balls in their tires to help balance them out . Or maybe try to engineer a way to put a second steering stabilizer on .

Thanks but I've heard that the golf balls eat up the inside of the tires, but I could always use bbs. I thought about adding a second stabilizer, but feel that is going to just mask the problem and or it won't work and I will be out of more funds

[MuddFoot]

ok i had the rr steering on my xj i built i had a little dw i used this http://www.jcroffroad.com/product/STR/PLYBSH.html put at your lower drag link on the rr setup i would order 2 uncase you break one i have and drive home sucks.. my build of that cherokee is on cherokeetalk.com under pizzaman3872 build think i have my setup on there

[MuddFoot]

also have your tires trued

[onlyinajeep726]

Steering stabilizers just mask the problem and only work for a short time, if they even help at all.  I can tell you right now that that RC adj. trac-bar is something I'd be worried about.  I don't know if you got the double shear bar (the one with the heim joint at the axle end), but if you do, take it from someone who has used one (ME), and get yourself something more beefy with a joint joint.  RE 1660 Extreme should do the trick. 

[MuddFoot]

or an ironman andys  had one on my xj super beef http://ironman4x4fab.com/Products/TB.html

[Wrz]

Steering stabilizers just mask the problem and only work for a short time, if they even help at all.  I can tell you right now that that RC adj. trac-bar is something I'd be worried about.  I don't know if you got the double shear bar (the one with the heim joint at the axle end), but if you do, take it from someone who has used one (ME), and get yourself something more beefy with a joint joint.  RE 1660 Extreme should do the trick. 

Thanks for the input, is there anyway to check to see if its my tb causing the wobble? It has less then 5 miles on it, I've had good experience with the iron rock offroad double shear bar in the past. Would I need a whole new trackbar or would I be ale to just purchase the re1660 joint and use it on my current trackbar

[shelbyluvv]

What are the specs on the alignment? The RC track bar is subject to me. They had issues with the bushings being too soft.

[Wrz]

What are the specs on the alignment? The RC track bar is subject to me. They had issues with the bushings being too soft.

I posted a picture of the alignment specs in my first post, I have a spare jks tb ill see if I can get it installed tomorrow and see if there's any difference. Would a trackbar drop bracket on the frame side help the geometry

[shelbyluvv]

You have too much caster. You want about 6* not almost 9 1/2*. My LJ also likes a touch of toe out too.

[ftpiercecracker1]

OP, if you would please, take several pictures of your steering setup. 4.5" is a good bit of lift and MJs are notorious for having driving/death wobble related issues after lifting so it may have something to do with your steering geometry.

 

Have no fear, for we shall prevail! :USAflag:

 

 

FPC

[onlyinajeep726]

The RE johnny joint will in no way fit into the RC trac-bar.  The RC bar itself is something like 0.75" hollow steel bar.  The RE extreme bar is solid and 1.25" thick.  You can buy a JJ from Currie Enterprises, but you'd have to find the correct threading, size, etc.
 
Also, like shelbyluv said, your caster is hella high...  I imagine that has a lot to do with it too.  One thing to consider also is that any alignment done at a regular car shop is going to be set and compared to manufactures specs at stock height.  Since your Jeep is lifted, you're going to have to do it a little different.  If there is a creditable 4x4 shop around you, get your alignment done there.  They will be far more knowledgeable with something like this because that's their specialty.
 
I also notice that your tires are running 35+ psi.  I know this is a little crazy sounding at first, but bigger tires need less pressure (Boyle's Law).  If you try to put the factory recommended amount of pressure in larger tires, that will contribute to death wobble.  Believe me, I just went through all this crap last year with my XJ.  I have four inches of lift on 31's.  I had the RC double shear trac-bar, my tires were running higher psi and my toe in was just awful, although my caster was acceptable.

 

Would a trackbar drop bracket on the frame side help the geometry

I'm not sure what you mean here. The RC trac-bar should have its own frame side bracket, which should already have a drop built in. Basically, for good steering geometry, your trac-bar and drag link should be parallel. You may consider a drop pitman arm on the steering box to achieve this.

[Eagle]

Are your new lower control arms stock length, or custom length?

 

I don't trust your alignment guy. How did he manage to adjust the camber on a vehicle that doesn't have any adjustment for camber? And how did you get caster that's MORE than the maximum desired range after lifting 4-1/2"? Lift reduces caster, which is one of the reasons for using adjustable lower control arms.

 

That said, with that much caster (if it's true) your alignment shouldn't be the problem. It's too LITTLE caster that sometimes contributes to death wobble. I know  that many people don't agree with me, but IMHO the only thing that causes death wobble is out of balance tires/wheels. Other stuff like track bars and tie rod ends may be less effective at masking death wobble when they're worn, but they don't "cause" death wobble.

 

Poorly balanced tires DO cause death wobble. And just because you paid big bucks to have your tires balanced on the latest equipment doesn't mean they are balanced. Too many "technicians" today took a 45 minute class on how to run the machine and they think the machine can do it all, with no thought on the part of the operator. Not true. The operator has to know what he's doing.

[Wrz]

Ftpiercecracker1- Hey ill post some pictures as soon as I get out of work, hopefully someone may see something I'm missing.

 

Onlyinajeep76- So it looks like I will be needing a new tb, the shop I use is a pretty reputable shop, unfortunately I do not know of off roading shop in my area. The owner said he set the caster really high because it will help reduce the chance of dw and shakes? I'm pretty new to the numbers and what they mean for the front end, so I'm learning as I go.  yeah my new track bar did not come with a new bracket. the total cost of it was $135 shipped to my door ( I guess I got the cheaper one )

 

Eagle- the lower control arms are meant for a 3-3.5 lift, I'm not sure how he got the camber so high, I think he said he removed the shims behind the lower control arm on the frame side. I'm going to see if I can sway my rims and tires with the ones from my dd and see if that helps

[Eagle]

Eagle- the lower control arms are meant for a 3-3.5 lift, I'm not sure how he got the camber so high, I think he said he removed the shims behind the lower control arm on the frame side. I'm going to see if I can sway my rims and tires with the ones from my dd and see if that helps

 

Well, that's not right. I asked about caster, not camber. Camber is not adjustable on the MJ.

 

He didn't change the caster. It was 9.4 degrees before and 9.4 degrees after. On both sides. His chart says the acceptable range is 5 degrees to 9 degrees. The factory service manual says the acceptable range is 7 degrees to 8 degrees, with 7-1/2 preferred. And removing shims from behind the LCAs would reduce caster, not increase it.

 

Despite all that, a lift often creates death wobble due to not enough caster angle. It's unlikely that too much caster would result in death wobble (although it certainly isn't good for the front driveshaft u-joints). That's why I think you should be looking at tire balance. If the same shop that did this alignment also did the tire balance, I'd suggest finding a different shop.

[Timeless]

Caster or track bar bushing/bracket is loose.

 

On my last XJ the track bar bracket came a bit loose from the frame and I mean barely.  I had death wobble like mad.  Welded the bracket to the frame, problem solved.

[Wrz]

Caster or track bar bushing/bracket is loose.

 

On my last XJ the track bar bracket came a bit loose from the frame and I mean barely.  I had death wobble like mad.  Welded the bracket to the frame, problem solved.

 

 

Eagle- the lower control arms are meant for a 3-3.5 lift, I'm not sure how he got the camber so high, I think he said he removed the shims behind the lower control arm on the frame side. I'm going to see if I can sway my rims and tires with the ones from my dd and see if that helps

 

Well, that's not right. I asked about caster, not camber. Camber is not adjustable on the MJ.

 

He didn't change the caster. It was 9.4 degrees before and 9.4 degrees after. On both sides. His chart says the acceptable range is 5 degrees to 9 degrees. The factory service manual says the acceptable range is 7 degrees to 8 degrees, with 7-1/2 preferred. And removing shims from behind the LCAs would reduce caster, not increase it.

 

Despite all that, a lift often creates death wobble due to not enough caster angle. It's unlikely that too much caster would result in death wobble (although it certainly isn't good for the front driveshaft u-joints). That's why I think you should be looking at tire balance. If the same shop that did this alignment also did the tire balance, I'd suggest finding a different shop.

 

Sorry i must have over looked caster for camber, I'm going too rotate my tires tomorrow morning and go for a drive, the right front has way to many weights on it, well over 6 ounces. Would this also cause it pull to the right? it never pulled before but now it does since ive picked it up from the shop

[Wrz]

Empty Post

[shelbyluvv]

Looks like a drop pitman arm with a stock track bar mount. They need to be dropped the same amount. If you drop one the other must be dropped too.

 

At 4.5", 7* of caster is preferred.

[benjy_26]

The heck is THAT broken bracket attached to?!?!?!?!?!?

[HOrnbrod]

Looks like a drop pitman arm with a stock track bar mount. They need to be dropped the same amount. If you drop one the other must be dropped too.

 

At 4.5", 7* of caster is preferred.

Yeah Bo, thinking the same. You need the track bar and drag link as close to parallel as possible as in the pic below. You don't have a pic wide enough to see the total relationship. The geometry looks wrong from what I can see due to the dropped Pitman. 

 

[onlyinajeep726]

 

Looks like a drop pitman arm with a stock track bar mount. They need to be dropped the same amount. If you drop one the other must be dropped too.

 

At 4.5", 7* of caster is preferred.

Yeah Bo, thinking the same. You need the track bar and drag link as close to parallel as possible as in the pic below. You don't have a pic wide enough to see the total relationship. The geometry looks wrong from what I can see due to the dropped Pitman. 

 

 

 

 

You can kind of see the drag link and trac-bar in the picture below.  Definitely not parallel as you and I have suggested. 

 

[Rockfrog]

The bends on the trac bar make it look right out ... but it doesn't look that far off overall .. you have to go from mount to mount, not the actual visual comparison.

The inverted T steering arangement likely isn't helping.

 

Having chased death wobble all over hell and back on my XJ ... it could be anywhere. It all adds up. The extra control arm angles due to lifting compound and accelerate the issue.

 

A trac bar alone won't do it, but anything else out with a tracbar issue will. Have you looked atbthe upper control arms? If they are worn they will cause enough axle shift to start deathwobble.

Lower your tire pressure as mentioned ... at 35psi the tires will also feel twitchy enough to start an episode. Try 30 or even 28psi ... heck I run 26psi in my 35's on my XJ.

In the end I cured my death wobble with a homebrew long arm 3 link conversion. The biggest change ... lower control arm operating angles and new beefire control arm joints (all are large RE cartridge joints). When we tore it apart we found worn upper arm bushings and a flexing trac bar mount. All added up to wicked ... crap your pants death wobble.

On the other hand ... when I bought my MJ the tracbar had 1/2" of pay in the balljoint end ... and not a single hint of deathwobble up past 140 km/h ... the XJ was a death wobble king at 80km/h ...

 

[dave92cherokee]

If the readings are true that he gave you then it seems like the axle is twisted. If you look at the control arm mount pictures one side only has one shim and the other has a stack of them. My first recommendation would be take it to a different larger auto shop to have the tires balanced and alignment checked. The other thing that concerns me is the readings for the rear, its a straight axle how could the toe be out like it shows on the print out.