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Discussion Starter #1
So I've researched all of the threads and have kind of, narrowed my solutions down but need a little help figuring out which direction to take. A few months ago, I had my Nitto Trail Grapplers (295/70r/18) and Rockstar Wheels installed. Everything rode great except the bump steer became much more pronounced. I had it re-aligned and a new steering stabilizer installed. Did not make much of a difference. Earlier this week I had my Old Man Emu 2.5" suspension lift installed. Now the bump steer is even more noticeable and the steering and handling is all over the place. Is this a case of fixing castor with adjustable control arms or drop brackets? Or am I looking at raising the trac bar and flipping the drag link? I'm going in to get another wheel alignment but with the way it's handling, I doubt that will be the ultimate fix. Any and all help is greatly appreciated. I wasn't looking to go crazy with my upgrades, just a little height. Now saftey seems to be an issue and this is my daily driver. Thanks!!
 

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Fixing the castor is the fix for your lift. Either Rancho or aev have an option. Rancho IMO is a better part. Or the more expensive adjustable controll arms.
Also chk tire pressure. Try about 28 psi.
 

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Bump steer is not caused by an incorrect Caster angle. It is caused by coupling vertical and lateral motion of the steering. The brackets will significantly help the dumpster. They will also indirectly have mild impact on the Caster angle. To directly correct the Caster angle use lower adjustable CAs.
 

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Bump steer is not caused by an incorrect Caster angle. It is caused by coupling vertical and lateral motion of the steering. The brackets will significantly help the dumpster. They will also indirectly have mild impact on the Caster angle. To directly correct the Caster angle use lower adjustable CAs.
wait... his dumpster angle is wrong too? oh this can't be good....
 

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Install the Rancho Drop Brackets..
Without more info, they are the easiest, stoutest, least expensive way to return geometry to manageable specs.
And btw, they correct more than caster angles..
 

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Discussion Starter #7
Hey, don't making fun of my dumpster! (And I have a "her" not a "his." Just some useless FYI.) I was going to get the Rancho brackets but I'm not sure if I also should get the lower adjustable CA's. Perhaps start with the brackets and then decide? I obviously don't want to spend any more than I have to but I also want to do it right.
 

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i'm not making fun of your dumpster, just saying a few dumpster correction brackets will help out a lot...

 

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How much height did you get from the coils ?
Bumpsteer is not something that's really prevalent at 2.5

Flighty/loose steering IS and fixing caster will solve your issues.

The argument control arms vs drop brackets, well that's up to you.
Clearance loss due to the brackets is a big deal for some. If you're not wheeling rocks or jeep is 100% daily driver, install brackets.
Drop brackets alter geometry ie instant center and place the arms flat to the ground bettering handling.
Adjustable lowers rotate the Housing for caster/pinion depending which way you go.
I see no reason not to spend $100 on drop brackets. If they become a issue... No big loss.
 

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Discussion Starter #13
I think I probably ended up almost 1/2" - 1" more than the 2.5". The very reason I went with a relatively minor lift is because I didn't want to sacrifice too much maneuverability (like needing to slow down to 20mph on curves) because I do drive it every day. I'm hoping the extra bit of height isn't going to cause too much of an issue.

The bump steer was very noticeable after the tires were installed (and the ball joints were replaced as well) but it was only bump steer. Now I am fighting that wheel to stay in control. And taking curves right now is downright scary.

I'm running 30psi right now. And I did order the drop brackets so I'm praying they correct the issue. If not, I guess I will be looking into new arms.

Thanks for the input, guys.
 

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At 3-3.5 inches of actual lift, you're caster is probably the problem with the flighty steering, etc. The drop brackets are the ticket. Adjustable control arms work too but they are more expensive and AEV says:

Please note: Adjustable Control Arms are not a replacement for drop brackets - Its often misunderstood that higher priced adjustable control arms have the same effect as AEV's control arm brackets and that the brackets are just a cheaper option than providing adjustable control arms. Nothing could be farther from the truth, both components do separate and different things and both have their place under a Jeep. Both products can adjust the castor angle which is where much of the confusion stems from.

AEV's drop brackets change four distinct parameters:

  1. - Lowers arm angle for ride quality.
  2. - Lowers the instant center for better braking (antidive).
  3. - Decreases operating angle of the driveshaft by reducing the range of travel.
  4. - Corrects caster angles.
Adjustable control arms can certainly allow the proper caster angle to be dialed in, however they are incapable of all the other parameter changes, and in fact make the instant center, ride quality and driveshaft angles all worse than stock. Adjustable control arms can do some things that the drop brackets can not:

  1. - Move the axle position forward or aft which may be required with aftermarket HD axles.
  2. - Change the pinion angles for aftermarket Cardan or Double Cardan driveshafts.
  3. - Correct minor deviations in suspension geometry after an accident with mild frame damage.
I've got the Rancho brackets and they cured my flighty steering and brake dive after my 2.5 inch lift.

Bumpsteer is probably another issue if it showed up before the lift. Did you replace the stock control arm and track bar bolts?Since it showed up when you got new tires, I'd start there, air pressure, alignment, maybe just new tires with stiffer sidewalls.
 

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I just bought a 14 JKU with a 3.5" pro comp lift and 35x12.50 open country tires. I just kinda thought the bump steer was normal and also the car would wonder around in the lane. After reading this thread I checked my tire pressure and the dealership had them inflated to 42 PSI! I couldn't believe it. I let them down to 32 and it made all the difference in the world in the way the car drives. No more bump steer or side to side movement when going straight. I am going to play around with pressures til I find one that I like the best but 32 seems to be 100 times better than it was before.
 

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Yeah, my tires came overinflated from the dealer too. I think my BFG KM's were at 42. I run them at about 34. I really don't know how they felt before. I reduced the pressure as soon as I got home. I noticed it playing with the EVIC in my driveway.
 
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