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Discussion Starter #1
So with my new 3in teraflex lift, Im getting wheel wobble at any bump over 40mph. I have a skyjacker steering stabilizer, and 4-6in lift pitman arm. I was originally supposed to get a 4in lift, hence the bigger pitman arm. Would that cause the wobble? And if not, what would? Thanks
 

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So with my new 3in teraflex lift, Im getting wheel wobble at any bump over 40mph. I have a skyjacker steering stabilizer, and 4-6in lift pitman arm. I was originally supposed to get a 4in lift, hence the bigger pitman arm. Would that cause the wobble? And if not, what would? Thanks
The pitman arm, probably not. Ck. every bolt on the front suspension especially the track bar, everything must be torqued down. Also ck. wheel balance and the welds on the track bar bracket on the axle.
 

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The front track bar is stock along with the bracket, the rear needs to be welded into place. Alignment is good, but the torqued bolts were only as much as I could.
 

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I would guess that it may be the Caster angle, possible in combination with the alingmet. Do you get death wobble at certain speeds, all the time or just on bumpty roads.

I am a few :beer::beer::beer: so sorry if that post made no sense. I will crawl back in my hole now...............
 

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Could be caster like WTF_LOL said. Especially if you've noticed it just since the lift was installed and not before.
 

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Caster and Toe might cause this. Since you got a larger ptman arm was it really needed? Did it come with the kit?

I would bet your axles are also not centered with that size lift. Did you check the front to see if it is centered? Advice when checking, don't use the outside of a rubber tire with a piece of wood. Instead take off both tires. And use the brake rotor as the plane to measure against as it likely more accurate and without as much imperfection. Take to pieces of aluminum squared at 18" length and rachet strap them tight on each ends to the other side. They should provide a good picture of toe and a good plane to check centering of the tires.
 

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Discussion Starter #7
I would guess that it may be the Caster angle, possible in combination with the alingmet. Do you get death wobble at certain speeds, all the time or just on bumpty roads.

I am a few :beer::beer::beer: so sorry if that post made no sense. I will crawl back in my hole now...............
The wobble happens above 45mph when I hit bumps. Its bad sometimes, and not so bad other times.


Caster and Toe might cause this. Since you got a larger ptman arm was it really needed? Did it come with the kit?

I would bet your axles are also not centered with that size lift. Did you check the front to see if it is centered? Advice when checking, don't use the outside of a rubber tire with a piece of wood. Instead take off both tires. And use the brake rotor as the plane to measure against as it likely more accurate and without as much imperfection. Take to pieces of aluminum squared at 18" length and rachet strap them tight on each ends to the other side. They should provide a good picture of toe and a good plane to check centering of the tires.

The pitman arm didnt come with the kit. I purchased it originally through quadratec when I was getting a 4in skyjacker lift, but since they were back ordered, I had already recieved the pitman arm and decided to throw it on anyways. Im really new to all this and unfortunetly dont have a steady source of information on this island yet. With this being said, I'm trying to figure out this caster angle stuff. I am not totally understanding what you are saying, but if you made a step-by-step instruction (with pics) im sure me and the rest of the internet community would really appreciate it.

I also just recieved my adjustable front track bar. Using the information I got from you and other online sources, I'm guessing I am also going to need to re-center my front axle. Will this help any with my wheel wobble?

Thanks everyone for all the input...
 

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Are you using a drop pitman arm without dropping the frame side track bar bracket? If so, that's probably the cause of the bump steer to begin with, but I'd check all your suspension bolts as well.
 

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Are you using a drop pitman arm without dropping the frame side track bar bracket? If so, that's probably the cause of the bump steer to begin with, but I'd check all your suspension bolts as well.
Ya, I havent done anything at all to the front track bar or bracket. How do you drop the bracket? BTW, I did just recieve my adjustable front track bar bracket. I havent installed it yet, but do you think it will help?
 

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Are you using a drop pitman arm without dropping the frame side track bar bracket? If so, that's probably the cause of the bump steer to begin with, but I'd check all your suspension bolts as well.
Gonna agree with this. If you've added a pitman arm and the trackbar and draglink angles aren't parallel any longer, this is probably the issue you're having.
 

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Gonna agree with this. If you've added a pitman arm and the trackbar and draglink angles aren't parallel any longer, this is probably the issue you're having.
Thanks for the info. Took the new pitman arm out tonight and put the old one back in. I also put in the adjustable track bar. This pretty much cleared up all bump wobble. This time I had a certified jeep mech to help me (or me help him). I also found out the placement of my steering stabilizer wasent making it completly utilized since I did have it an an angle. So things are definetly looking a lot better. Thanks for all the help guys...
 

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Death Wobble or Bump Steer?

Looks like you had may have had bump steer. That's when the geometry of your track bar and your drag like don't make a perfect parallogram so your wheel pulls to one side or the other when the suspension is compressed or extended. JR mentioned that in his post. Perfect" actually doesn't really cut it, since the dynamics of the moving vehicle change the geometry a little from what it looks like in static conditions like when it's sitting on the garage floor. I've had to re-engineer one suspension system set up by engineers who hadn't thoroughly tested it before delivery. It looked good on paper (their computer models) but scared you when you hit bumps. That's why Ford and others still have test tracks.
If you actually had "death wobble" (see http://hoodlift.com/Deathwobble.html for a short article on it), you may have fixed it by replacing something loose or masked it by increasing the efficiency of your steering dampener. If you have only masked it, doing the thing where you have someone turn the wheel back and forth while you feel each joint for looseness plus look for anything else loose under there should be in order. On the JK, the front upper control arm where it attaches to the axle can sometimes get a little loose and the bolt can cause the bolt hole to elongate. It's hard to see but will cause "death wobble". One fix is to reweld and drill out the bolt holes, then weld the nut to the control arm bracket once it's all tightened back up again to prevent it elongating again. Here is a photo of that upper arm and passenger side bracket with the nut welded to the bracket and painted black.
Yeah I know, this is long, but I hope it helped someone, at least.
 

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Death Wobble or Bump Steer?

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Looks like you had may have had bump steer. That's when the geometry of your track bar and your drag like don't make a perfect parallogram so your wheel pulls to one side or the other when the suspension is compressed or extended. JR mentioned that in his post. Perfect" actually doesn't really cut it, since the dynamics of the moving vehicle change the geometry a little from what it looks like in static conditions like when it's sitting on the garage floor. I've had to re-engineer one suspension system set up by engineers who hadn't thoroughly tested it before delivery. It looked good on paper (their computer models) but scared you when you hit bumps. That's why Ford and others still have test tracks.
If you actually had "death wobble" (see http://hoodlift.com/Deathwobble.html for a short article on it), you may have fixed it by replacing something loose or masked it by increasing the efficiency of your steering dampener. If you have only masked it, doing the thing where you have someone turn the wheel back and forth while you feel each joint for looseness plus look for anything else loose under there should be in order. On the JK, the front upper control arm where it attaches to the axle can sometimes get a little loose and the bolt can cause the bolt hole to elongate. It's hard to see but will cause "death wobble". One fix is to reweld and drill out the bolt holes, then weld the nut to the control arm bracket once it's all tightened back up again to prevent it elongating again. Here is a photo of that upper arm and passenger side bracket with the nut welded to the bracket and painted black.
Yeah I know, this is long, but I hope it helped someone, at least.
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2007 Flame Red Unlimited, 3 1/2" Black Diamond Lift,Terraflex adjustable control arms, Premier Power Welder with 2nd alternator and separate battery, lotsa custom under-armor, custom exhaust, 2 sets of 35" BFG MTs, one set on Champion beadlocks, Off Road Logic roof rack, Rock Hard Bumper, Warn rock sliders, Kilby front bumper with Warn Power Plant winch, Power tank for the air tools, corner armor, CB and shortwave (KI6FUG) HoodLift.

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Last edited by JimP; May 18th, 2008 at 01:02 PM.

JimP,

I think my current config meets your definition of bump steer condition.I have a rubicon express 4.5 long-arm kit. RE says drag link can be mounted to the top of the knuckle. I think that would bring it closer to parallel to the track bar. What do you think? Thanks RobV
 

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Rob, It looks like it might fix it. Those I've seen with the kind of geometry yours appears to have usually have some bump steer.
Did Rubicon Express mention whether your tie rod ends are tapered and how to address flipping them to the top of the knuckles? I don't know how the JK does it, but older Jeeps have a tapered hole in the knuckle that the tie rod and drag link attaches to. If that's the case on the JK, you will have to get tapered shims that go into the hole if it's drilled out with a straight drill. You can find these online. Rubicon Express may also have a handle on that. Another way is to just run the correct tapered ream down through the top; however you lose about 1/2 the contact patch inside the steering knuckle doing it that way unless you get larger tie rod ends. With the aftermarket tie rod you have, that looks possible. Is that a Rubicon Express one?
Some of the following doesn't cause bump steer, but, if you haven't addressed these issues yet you can get some weird steering quirks.
Did you go through the drill of setting your new adjustable track bar so that all left-to-right measurements are equal when the Jeep is on the ground? I use lead fishing weights on strings and suspend them from points on the chassis that are the same on each side and measure to corresponding identifieable points on the axle to make sure the axle is truly centered when the Jeep is sitting at ride height. That's a good start. Then, if you have access to a lift, slowly raise the vehicle and see if the steering wheel turns while the suspension is extending. In a perfect world, it will stay straight, so long as the wheels aren't getting some turning force from not being on the lift straight in the first place. If the steering wheel pulls very much, you can experiment with longer or shorter track rod positioning to see if that helps.
Then go drive it on a little-used road and see if it pulls left or right on braking compression or acceleration. You want to see if it pulls the same on a compression bump as it does on braking. If it's different, then your brakes could be suspect. If you see a consistant pull on compression bumps and the opposite pull on accel (as the front end lifts) try a different postion for the track rod and see if it's worse or better. You may be able to sneak up on the "sweet spot."
If all that doesn't do it, and it probably will, you have to change the point where the track rod mounts, usually at the axle end. That would mean fabbing and welding new mounting points, but I don't think that will be necessary.
When I did the R&D after converting a CJ first to coils, then to air bags, I made a test-jig track bar out of angle iron with lots of holes in it. I also set up more than one mounting point on the axle. After first doing the math I then experimented with different positions until finding the sweet spot. Then made the final track bar to that length and mounted it the right location. The guy who drove it to Colorado from Sacramento said he realllly liked how straight it went down the road.
That exercise and the one fixing the suspension that the large corporate engineers with all their computer modeling did showed me that you sometimes just have to get out there and test to get it right.
Then there is setting the toe-in (I use 1/4" toe in measuring on the tires)
With that much lift, you did reset the castor, right? As I recall it should be about 4 degrees negative but without looking it up, I could be wrong.
Be sure to re-center the steering wheel as the last thing after making the adjustments or your computer will think you are in a skid and turn on a couple of warning lights.
Lastly, if you would like to make a cheap, dandy toe-in tester, let me know. I'll show you how.
 

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Please let us (me) know what you come up with. I just put on a 2.5” BB and hit a bump going 50 on a curved onramp. It scared the CR&P out of me. I am going to re torque everything this weekend but I have not got a re alignment yet. I was told with the small of a lift I would not need anything but the spacers but now I am a little concerned about long trips with my kids in the car. :bawling:
 

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Please let us (me) know what you come up with. I just put on a 2.5” BB and hit a bump going 50 on a curved onramp. It scared the CR&P out of me. I am going to re torque everything this weekend but I have not got a re alignment yet. I was told with the small of a lift I would not need anything but the spacers but now I am a little concerned about long trips with my kids in the car. :bawling:
You more than likely need to buy an adjustable track bar or relocation bracket to get the trackbar/draglink parallel again. If they aren't parallel, bumpsteer will ensue.

I test drove the Warrior 3" lift kit that uses a relocation bracket pretty extensively in a 08 2 door X and it steered great and rode excellent, no bumpsteer at all.

http://www.rjroffroad.com/warrior-t...jeep-wrangler-offroad-c-557-p-1-pr-17305.html
Price runs $43.79 for the relocation bracket kit for the front. Keep in mind it was designed on the 3" lift kit, so I am not sure how properly it would align the trackbar for 2.5"

http://www.rjroffroad.com/warrior-r...jeep-wrangler-offroad-c-557-p-1-pr-17306.html
There's the rear bracket too. Only $19.99!
 

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Please let us (me) know what you come up with. I just put on a 2.5” BB and hit a bump going 50 on a curved onramp. It scared the CR&P out of me. I am going to re torque everything this weekend but I have not got a re alignment yet. I was told with the small of a lift I would not need anything but the spacers but now I am a little concerned about long trips with my kids in the car. :bawling:
When the scary thing happened, did your Jeep try to turn in one direction (bump steer) or did the wheel start shaking violently? (death wobble). I think you are talking about bump steer, but if it's death wobble you don't really want to drive it until you find what's loose under there. JR is right about having to get the geometry right again. On my Unlimited with a 2" spacer lift on the front and a 1.75" spacer lift in the back there was just a tiny litttle bump steer with stock, non-adjustable track bar and no relocation brackets. However with the 3" lift on there now the adjustable front track bar was necessary. It also came with a relocation bracket for the rear and cams to put on the lower control arms to correct the caster (and they sucked! I replaced the lower control arms with adjustable ones 'cause cams are notorious for not staying put) Your lift is in the middle so you probably need an adjustable front track bar or, at the least, a relocation bracket. With the site JR's post leads you to, you get someone who did all the engineering; however, as he says that was for a slightly lower lift. You could try calling some of the suspension manufacturers and see what they suggest.
 

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Rubirobv,
Taking another look at your photos, it looks like your track rod bracket is dropped a bunch where it ties into the frame. Is that newer-looking bracket RE aftermarket? I might be wrong here, but it looks like you can move the frame end of the track bar up into that bracket more by drilling another set of holes abt 1/2 way between the ones that are there. That would get your track bar more parallel. Then centering the axle with the adjustments in the track bar while sitting on the ground could improve the bump steer. Or not, but it's something I would take a good look at. I have a lot of respect for RE's engineering so think they had a good reason for lowering your driver's side track bar so far. I just don't know what it was.
 

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When the scary thing happened, did your Jeep try to turn in one direction (bump steer) or did the wheel start shaking violently? (death wobble).
I see the relocation bracket is for a 3” lift. That makes it off by .5” but without it I am off by 2.5”? Wouldn’t it be better with the bracket?
 
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