Changing Springs

[mrcabinet]

My '01 TJ, with a 4" Pro Comp lift, has always sat 3/4 to 7/8 low in the back with the hard top and 33" spare. Plus, I've never liked the way the steering acts with the 4". I'm toying with the idea of changing the front springs to 3" BDS or Rusty's springs. I think that this would level it out and, hopefully, improve the steering some. Should I be concerned about the LCAs that were installed with the 4" kit? Anything else I should consider before doing this?

[sharpxmen]

did you get the drop pitman arm and trackbar bracket installed on the axle? - if you didn't then that might be your steering problem.

[neale_rs]

What are LCAs?

[mrcabinet]

Track bar, yes. I tried a dropped pitman arm and it was horrible. I'd like to get back some of the "return to center" feel from the steering. A lot of shops and people I've talked to say going over 3" on a TJ is when you start getting issues, so I thought it might be worth trying.

LCAs are lower control arms.

[sharpxmen]

Track bar, yes. I tried a dropped pitman arm and it was horrible. I'd like to get back some of the "return to center" feel from the steering. A lot of shops and people I've talked to say going over 3" on a TJ is when you start getting issues, so I thought it might be worth trying.

LCAs are lower control arms.

return to center or straight line stability is given by the caster angle, your lift might have affected that - on the other hand if you readjust the caster angle closer to stock you might have an issue with the driveshaft to pinion angle, might want to verify these, maybe find a happy medium between the 2.

[neale_rs]

My '01 TJ, with a 4" Pro Comp lift, has always sat 3/4 to 7/8 low in the back with the hard top and 33" spare. Plus, I've never liked the way the steering acts with the 4". I'm toying with the idea of changing the front springs to 3" BDS or Rusty's springs. I think that this would level it out and, hopefully, improve the steering some. Should I be concerned about the LCAs that were installed with the 4" kit? Anything else I should consider before doing this?

I think the 3" springs would work fine to level the Jeep or you could add spacers in back (cheaper).  The installation of the control arms may have changed the caster so it could be causing the steering problems.  The steering should be fixable.  A 4" lift for a TJ is pretty common and many have gotten it to work.

[Bounty Hunter]

I doubt the 3" springs will change your steering issue one bit, I'd add a 1" spacer to the rear springs and work your way through the steering problem the correct and most direct way.  Replacing springs is a very indirect way to try to alter the steering characteristics.

Caster, as was already mentioned, has a lot to do with steering feel, as well as toe-in.  Have you had both checked?

[neale_rs]

In some magazines they recommed 1/8" toe-OUT, claiming it can help with steering wander.  It's pretty easy to do so you might want to try it to see if it works for you.

[dustjunkie]

The sagging back and the LCA will affect steering.  Dropping the front will add positive caster in itself and leveling it will do the same although less caster from the leveling.  The return to center is 100% from your caster angle and lifting it without lengthening the LCA's does that. 

[mrcabinet]

I've been through the entire front end and had two different shops verify my findings (or lack of). Caster angle is the only thing left to try. I can get a pair of BDS 3" springs for less than a hundred bucks, which is alot cheaper than adjustable arms, so it is worth a try. If it doesn't work, you'll see the springs in the Garage Sale section!

[sharpxmen]

I've been through the entire front end and had two different shops verify my findings (or lack of). Caster angle is the only thing left to try. I can get a pair of BDS 3" springs for less than a hundred bucks, which is alot cheaper than adjustable arms, so it is worth a try. If it doesn't work, you'll see the springs in the Garage Sale section!

why don't you get one of those shops to verify the caster angle. if it turns out to be it then you need longer lower control arms or shorter uppers (or both).

[mrcabinet]

I've heard varying opinions as to what the angle should be with a 4" lift. What's the consensus here?

[Bounty Hunter]

5º-8º, the closer to 5º the better.

[mrcabinet]

According to the last shop it is at 5 degrees. Why is 5 better than 8? Don't most high end cars have them tweaked pretty far out?

[dwtaylorpdx]

MOst high end cars are planning on going faster than a Jeep 

Caster really affects the amount the wheels wish to return to straight.

Google TJ Death wobble I think this has been sorted out....

Dave