Steering stabilizers & Death Wobble

Okay, before you reach for the flame key on the keyboard please hear me out. I *have* searched and read and studied. And I'm very much aware the general concensus is steering stabilizers just mask an existing problem and that is *not* my question/problem...well sort of.

A little background: I recently moved my 2001 up to 4.5" from 3.5" with what amounts to an "upgraded" 4.5 RE Superflex Kit; meaning I got adjustable control arms instead of fixed and boomerang shackles (I kept my existing leaf springs since they're the same in the 3.5 and 4.5 kits). Along with this I put on new disconnects, the ORO U-Turn steering kit and a new OME Steering stabilizer. After getting everything tightened up and an alignment done everything was fine. Not too long after that I got ahold of an HP D30 from a guy in Santa Cruz for a pretty reasonable price (thanks Jed! ) and since I still had a few things left to do (Optima Yellow Top, RE HD Adjustable TB w/Brace, replace TRE on the ORO draglink since it showed up with a loose one) but had run out of time I decided to have a local shop to the swap (quick plug for Arabia's Overkill for anybody in the San Jose area - Jeff is a great guy and builds some incredible machines!).

The swap goes fine. Stuff is tight, the steering geometry looks good. I have a n HP D30 so I'm happy and it drives just fine on the way home (all surface streets) but the next day when I take it on the freeway I get one of the biggest scares of my life driving a car. At about 70 mph, I hit a few divits in the road (nothing major) and the front end goes nuts. I get off the freeway and go right back to the shop. They drop everything and start going over things. They find a couple of things right away, the brand new track bar seems to have a lot of play in the bushing where it attaches to the axle. That gets replaced. The castor is off quite a bit. That gets adjusted throughout the rest of the day by increments (glad I bought those adjustables ) with drives in between every degree or so. The tires get rotated and the pressure set (they were already balanced - remember I had been on the freeway before with no problem). Check the toe in again. Check the steering knuckles. Nothing helps.

We decide to start moving things back to the way they were when I brought it in so I drop it off the next day with the old trackbar (a JKS adjustable - I went with the RE for the mount and the brace), the first ORO draglink and I brought the original steering assembly for kicks. Swapping the draglink has no effect so we go back to the new new one. However, replacing the brand new OME steering stabilizer with the stocker does. No more DW. Now, I would have thought (perhaps naively) putting the stock stabilizer on would have made things worse not better but apparently thats not the case. At this point, everything looks right: stuff is tight, alignment is good, tires are good, damn near everything up front is new and I didn't have this problem with essentially the same setup.

So, my question(s):
Why would the stock SS make this go away (or at least mask it better) than the OME?
Has anyone else seen this where the only significant change was going from a LP D30 to an HP?
Is it possible adding the track bar brace has some effect?
I did have a C-ROK inner steering plate put in, is it possible something happened with the steering box which could cause this?
What else can we check?

Any ideas would be appreciated. Thanks.

--mike

did you check the angle of the front pinion? that is a big fat culprit of death wobble. usually when lifting the xj the LCA's are extended in length. try rolling your pinion back a bit.

anything else , aside from worn parts, is a bandaid for the needed correction of front end geometry. make sure you set the length of the trak bar with the vehicle on the ground and after you have bounced it up and down a few times to settle everything in. lca's are to be tightened once vehicle is resting on wheels, not jacked up by the unibody.

make sure the alignment / toe in. (/ \) is within spec.

since you have adjustables, try lengthening lca's and go for a spin.

the steering stabilizer is more for bump steer. if you put one on and death wobble magically disappears its just masking something and will return or come back if you hit a bump just right or when the stabilizer gets worn.

On a healthy Jeep you don't need a stabilizer. I've run 31s t o35s on my DD XJ without a stabilizer with zero issues.

ZachMan said:

On a healthy Jeep you don't need a stabilizer...

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what an ignorant comment. You think Jeep put one on every new XJ to increase their manufacturing costs :dunce:

POSXJGuy said:

did you check the angle of the front pinion?
... since you have adjustables, try lengthening lca's and go for a spin.

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"The castor is off quite a bit. That gets adjusted throughout the rest of the day by increments (glad I bought those adjustables )"

POSXJGuy said:

the steering stabilizer is more for bump steer.

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can you back up that statement with something beyond your IE degree and old wives tails?

MaXJohnson said:

"The castor is off quite a bit. That gets adjusted throughout the rest of the day by increments (glad I bought those adjustables )"


can you back up that statement with something beyond your IE degree and old wives tails?

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what lame comments from a guy who didn't offer a damn tip whatsoever to help the guy who posted the issue with his xj.

if you think you are the one who knows more why don't you offer a hand with his issues then?

MaxGayJohson 3===> O :flame::flame::flame:'er


i think you are on the wrong board.

POSXJGuy said:

did you check the angle of the front pinion? that is a big fat culprit of death wobble. usually when lifting the xj the LCA's are extended in length. try rolling your pinion back a bit.

anything else , aside from worn parts, is a bandaid for the needed correction of front end geometry. make sure you set the length of the trak bar with the vehicle on the ground and after you have bounced it up and down a few times to settle everything in. lca's are to be tightened once vehicle is resting on wheels, not jacked up by the unibody.

make sure the alignment / toe in. (/ \) is within spec.

since you have adjustables, try lengthening lca's and go for a spin.

the steering stabilizer is more for bump steer. if you put one on and death wobble magically disappears its just masking something and will return or come back if you hit a bump just right or when the stabilizer gets worn.

Click to expand...

check yuccaman's site for LCA lengths you may need: http://www.yuccaman.com/jeep/re_db.html

MaXJohnson said:

what an ignorant comment. You think Jeep put one on every new XJ to increase their manufacturing costs :dunce:

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There is no way thats an ignorant comment, if you think so you're an idiot. I also suppose you think the stabilizer cures DW too :looser: I really will go more into this if you want to, but for now you're not worth it.

A steering stabilizer if it helps AT ALL will only help reduce the oscilating bumps after you hit a pothole (the small recovery bumps). You will still have DW though. There are several list floating around about common culprits, its bound to be one or several of them. Good luck, 70mph DW is more of a ride than u can find in an amusement park. Been there. :repair:

You talk about adjusting your caster by degrees, what did you end up with??

6* is spec if I'm correct isn't it?

Rocketman said:

You talk about adjusting your caster by degrees, what did you end up with??

6* is spec if I'm correct isn't it?

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I believe its at 5.5 now, down from about 11.5.

POSXJGuy said:

check yuccaman's site for LCA lengths you may need: http://www.yuccaman.com/jeep/re_db.html

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Yep, that site is what I used to set the control arm lengths when I put the lift on with the original axle. And, with the original axle, everything was fine. Its when we switched in the HP D30, things when haywire. Actually, I'm starting to think the RE HD Trackbar and the ORO steering kit don't place nicely together. The lines just don't look right although its tough to tell exactly because both the draglink and the trackbar have bends in them which don't really line up and the track bar is the only significant thing that changed when the new axle went under.

Thanks for the response tho.

POSXJGuy said:

did you check the angle of the front pinion? that is a big fat culprit of death wobble. usually when lifting the xj the LCA's are extended in length. try rolling your pinion back a bit.

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By "rolling your pinioin back", do you mean either shortening the lowers or lengthening the uppers so the pinion tilts more upward? I looked at that right after work and the pinion and shaft are pretty much in a straight line.

POSXJGuy said:

make sure the alignment / toe in. (/ \) is within spec.

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Toe in is at 1/8 which, from doing some net research, is within what the ORO folks suggest (1/16 - 1/8). Since its a cross over steering setup they say you don't need quite as much toe-in. But, I believe 1/8 is what the spec is.

POSXJGuy said:

the steering stabilizer is more for bump steer. if you put one on and death wobble magically disappears its just masking something and will return or come back if you hit a bump just right or when the stabilizer gets worn.

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I hear you, and this is exactly why I started the thread. The problem is I'm just not sure what to check next. We've checked hubs, joints, control arms, track bar, draglink, tie rod, alignment and rotated the tires and checked their pressure. Everything is tight and pretty much brand new.

I did notice one of the front wheels didn't have any weights on it so I'm going to get them balanced again tommorrow but the only way I see that having an effect is if the weights fell off when they removed the tires during the axle swap. Seems kindof unlikely (not impossible, but unlikely).

Nickster said:

A steering stabilizer if it helps AT ALL will only help reduce the oscilating bumps after you hit a pothole (the small recovery bumps). You will still have DW though.

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Yep, that's exactly what I'm afraid of. I'm just at a loss as to how it went away by putting the stock stabilizer back on instead of the OME. The OME is brand new and seems to be working just fine.

Nickster said:

There are several list floating around about common culprits, its bound to be one or several of them. Good luck, 70mph DW is more of a ride than u can find in an amusement park. Been there. :repair:

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You said it man! 15 minutes later standing around at the shop I went to pick something up and found I was still shaking. Didn't even realize it till then.

MaXJohnson said:

what an ignorant comment. You think Jeep put one on every new XJ to increase their manufacturing costs :dunce:

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Well, they did put a rear sway bar on there for some weird reason.

POSXJGuy said:

... why don't you offer a hand with his issues then?

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my contribution, offered without calling you "gay", is to point out that your post was pretty much useless mis-information.

ZachMan said:

There is no way thats an ignorant comment, if you think so you're an idiot. I also suppose you think the stabilizer cures DW too :looser: I really will go more into this if you want to, but for now you're not worth it.

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new (healthy) Jeeps roll off the assembly line with steering stabilizers. Are you capable of explaining why without resorting to name calling?

Nickster said:

A steering stabilizer if it helps AT ALL will only help reduce the oscilating bumps after you hit a pothole (the small recovery bumps). You will still have DW though. There are several list floating around about common culprits, its bound to be one or several of them. Good luck, 70mph DW is more of a ride than u can find in an amusement park. Been there. :repair:

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steering stabilizers reduce oscillations...
oscillations = DW
steering stabilzers reduce DW

if a = b & b = c, then a = c

mikep said:

Yep, that site is what I used to set the control arm lengths when I put the lift on with the original axle. And, with the original axle, everything was fine. Its when we switched in the HP D30, things when haywire. Actually, I'm starting to think the RE HD Trackbar and the ORO steering kit don't place nicely together. The lines just don't look right although its tough to tell exactly because both the draglink and the trackbar have bends in them which don't really line up and the track bar is the only significant thing that changed when the new axle went under.

Thanks for the response tho.

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the high and low pinion D30's don't have the same relationship between pinion angle and castor. If you replace a low pinion D30 with a high pinion D30 and you are trying to line up the pinion angle as your first guess for alignment, the castor will be off by several degrees. Sounds like you've worked that out now.

The ORO steering is known to increase bump steer as it raises and lengthens the drag link without a coresponding change in the track bar. The resulting increase in steering input when hitting a bump would increase the likelyhood of steering oscillations (triggering DW).