How can I correct BUMP STEER?
JK Enthusiast
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From: Some Place in Africa
JK Jedi Master
Joined: Aug 2007
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From: Hammond Louisiana
My bet is that your trackbar is flexing too much. As pluke said, you've got an awful lot of threads showing. Not enough bite to hold the TB steady maybe. Is that one of the newer jks or older ones. For a time , their first tb was found to be flexing and/or snapping in to. They did put out a revised one though.
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JK Super Freak
Joined: Mar 2009
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From: Scottsdale, AZ
My bet is that your trackbar is flexing too much. As pluke said, you've got an awful lot of threads showing. Not enough bite to hold the TB steady maybe. Is that one of the newer jks or older ones. For a time , their first tb was found to be flexing and/or snapping in to. They did put out a revised one though.
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JK Super Freak
Joined: Mar 2009
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From: Scottsdale, AZ
Oh man... I got some work to do now. I don't know what my caster is when COP4x4 installed my lower control arms, but the Jeep does drive pretty near straight with the Teraflex lower control arms; so much better than when the lift I had was shortly and temporarily running with factory control arms. I didn't even think about grabbing my alignment specs -- 
-- was too caught up in making sure every suspension component they checked was okay so I would never experience death wobble again.
As for tire psi, I'll check. I want to say it's roughly 28psi. I know that COP4x4 said my initial psi -- above 30psi -- contributed to the death wobble. Oh, really quick question: anyone ever hear of BFG A/T's having more contribution to DW than other brand tires?
As far as the trackbar goes, I hope the inside threading isn't messed up. I just bought it. Plus I had COP 4x4 lock-tight the jam nut after really tightening it. Last time I undid a lock-tighted nut, I almost popped my shoulder. I believe COP4x4 checked my trackbar though and said it was a-okay. I hope so as I don't want to purchase another after dropping all of this cash.
I will check everything else today in just a little bit. Thanks alot Planman, and everyone for trying to help me out.
-- was too caught up in making sure every suspension component they checked was okay so I would never experience death wobble again. As for tire psi, I'll check. I want to say it's roughly 28psi. I know that COP4x4 said my initial psi -- above 30psi -- contributed to the death wobble. Oh, really quick question: anyone ever hear of BFG A/T's having more contribution to DW than other brand tires?
As far as the trackbar goes, I hope the inside threading isn't messed up. I just bought it. Plus I had COP 4x4 lock-tight the jam nut after really tightening it. Last time I undid a lock-tighted nut, I almost popped my shoulder. I believe COP4x4 checked my trackbar though and said it was a-okay. I hope so as I don't want to purchase another after dropping all of this cash.
I will check everything else today in just a little bit. Thanks alot Planman, and everyone for trying to help me out.
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JK Super Freak
Joined: Mar 2009
Posts: 1,047
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From: Scottsdale, AZ
Update after testing
I had my dad turn the steering wheel 10 o'clock to 2 o'clock briskly, but not too fast. My drag link, where it connects to the knuckle, pops down when the steering wheel is at 2 o'clock and then pops back up when the steering wheel is at 10 o'clock. It is secure at the pitman arm.
Aside from that find, the trackbar is secure and in good shape. My tie road is pretty good too. There is no play in that either when turning the wheel, but when I grab it with my hands I can move it (more like twist it) up and down. It seems like it's suppose to do that, but I'd like to double-check that by you more knowledgeable experts.
Aside from that find, the trackbar is secure and in good shape. My tie road is pretty good too. There is no play in that either when turning the wheel, but when I grab it with my hands I can move it (more like twist it) up and down. It seems like it's suppose to do that, but I'd like to double-check that by you more knowledgeable experts.
Last edited by RN M OVR; Dec 12, 2010 at 08:05 AM.
Thread Starter
JK Super Freak
Joined: Mar 2009
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From: Scottsdale, AZ
Yes, the tie rod is supposed to be able to rotate so that the ends can accommodate suspension articulation.
Your bad drag link end on the knuckle side needs to be repaired. You would typically experience a non-DW type wobble in your steering with a bad knuckle side drag link end. You might also, have some feedback that might feel similar to bumpsteer.
Given that you aren't quite at 4" lift and that your drag link end is bad, I'd say that you probably do not need a drag link flip kit.
I'd buy either a Rubicon Express (RE2610) or Currie (JK-9701DL) drag link. They can both be run in the stock position or flipped (if you later do a flip approach). The Currie costs almost 2x as much, but it is that much better. The RE would work fine.
You could always just buy a stock replacement drag link as well.
So, fix the drag link problem first, then see how much of a difference that makes.
COP may have saved your alignment specs in their computer and could print them out at your request.
The BFG ATs are a great tire and would not contribute to your problem unless you have a blown radial belt or something. Rotating the tires front to back could test this.
Your bad drag link end on the knuckle side needs to be repaired. You would typically experience a non-DW type wobble in your steering with a bad knuckle side drag link end. You might also, have some feedback that might feel similar to bumpsteer.
Given that you aren't quite at 4" lift and that your drag link end is bad, I'd say that you probably do not need a drag link flip kit.
I'd buy either a Rubicon Express (RE2610) or Currie (JK-9701DL) drag link. They can both be run in the stock position or flipped (if you later do a flip approach). The Currie costs almost 2x as much, but it is that much better. The RE would work fine.
You could always just buy a stock replacement drag link as well.
So, fix the drag link problem first, then see how much of a difference that makes.
COP may have saved your alignment specs in their computer and could print them out at your request.
The BFG ATs are a great tire and would not contribute to your problem unless you have a blown radial belt or something. Rotating the tires front to back could test this.
Thanks again!
Thread Starter
JK Super Freak
Joined: Mar 2009
Posts: 1,047
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From: Scottsdale, AZ
Just your end is bad. The knuckle is fine.
Your handling would improve with a flip kit. However, there is a minimum amount of front extended bumpstopping required to run a flip kit due to the change in position.
From your pics, you appear to be running stock front bumpstops (no extensions on the lower spring pads).
Before you consider a flip kit, you need to find out from EVO, AEV, Tefaflex, Rock Krawler, etc., how much front extended bumpstopping they recommend to run their kits. They might suggest a minimum 3" or 3.5" front extended bumpstops.
You may not want to restrict your suspension up travel that much.
Your handling would improve with a flip kit. However, there is a minimum amount of front extended bumpstopping required to run a flip kit due to the change in position.
From your pics, you appear to be running stock front bumpstops (no extensions on the lower spring pads).
Before you consider a flip kit, you need to find out from EVO, AEV, Tefaflex, Rock Krawler, etc., how much front extended bumpstopping they recommend to run their kits. They might suggest a minimum 3" or 3.5" front extended bumpstops.
You may not want to restrict your suspension up travel that much.
Thanks again for everything. I'll make sure to update this thread once I make a phone call, a purchase of some sort, and the results.
Thread Starter
JK Super Freak
Joined: Mar 2009
Posts: 1,047
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From: Scottsdale, AZ
STEERING GEOMETRY image
I don't know how much this test with some string helps. I know the string is not perfectly where the mounting points are for the drag link and trackbar, but hopefully those with a good eye can help me. I did this test in order to help out my bump steer problem, which I am trying to solve -- also debating if I should do a drag link flip or just purchase a new, stronger drag link for the stock location... looks as if I don't need a drag link flip kit. But I'll let you all decide as I would rather be safe and comfortable than dealing with wheel-wobbles when hitting potholes and cracks in the road.
Planman, feel free to put in your .2 cents.
Below the Knuckle:
Above the Knuckle:
Planman, feel free to put in your .2 cents.
Below the Knuckle:
Above the Knuckle:
Last edited by RN M OVR; Dec 12, 2010 at 10:06 AM.