1999 Land Cruiser minor torsion bar adjustment results in steering shimmy

[CGH17374]

I installed OME 2865 coils a few months ago and cranked up my OEM torsion bars less than 1.5 inches and then had had it aligned. The steering became super light and I ended up with a shimmy in the steering wheel around 70mph. The shocks are new OEM, the UCA is original and I have not added a diff drop yet (I did notice my CV’s were leaking a little).

I have since cranked my TB’s back down and I’m now sitting at 19.25 inches at the front. My rear fender lip to center hub measurement is 21.5 inches with the new 2865’s. I Would like to get the front up to 20.5 inches resulting in one inch of rake and still leaving ample droop. The light steering and shimmy are now gone but my front end seems to be sitting lower now than factory specs.

I don’t want to spend a lot of money as this is an older high mileage (314K) mall crawler which I’ve owned since 2006. Any recommendations would be greatly appreciated.

 

[jLB]

Extremely light steering, and “not automatically returning to center” are usually indicators of not enough caster, often a side effect of too much lift, or a half-assed attempt at alignment.

I’d suspect worn bushings in the suspension and/or steering for the “shimmy”.

I always find the “trivial 1.5-2 inch lift” in the front amusing, because on the 100 series 2” seems to be on the ragged edge of reason.

 

[Mike NXP]

I installed OME 2865 coils a few months ago and cranked up my OEM torsion bars less than 1.5 inches and then had had it aligned. The steering became super light and I ended up with a shimmy in the steering wheel around 70mph. The shocks are new OEM, the UCA is original and I have not added a diff drop yet (I did notice my CV’s were leaking a little).

I have since cranked my TB’s back down and I’m now sitting at 19.25 inches at the front. My rear fender lip to center hub measurement is 21.5 inches with the new 2865’s. I Would like to get the front up to 20.5 inches resulting in one inch of rake and still leaving ample droop. The light steering and shimmy are now gone but my front end seems to be sitting lower now than factory specs.

I don’t want to spend a lot of money as this is an older high mileage (314K) mall crawler which I’ve owned since 2006. Any recommendations would be greatly appreciated.

My thought is that if the shimmy is gone and it's driving alright, just deal with a little stink bug look. Once you load some gear in the rear will settle down a bit.

Is 19.25" lower than factory? I thought 19-19.5 was about right ? Maybe go up a few hairs at a time and see if the shimmy starts up again?

 

[jLB]

Is 19.25" lower than factory? I thought 19-19.5 was about right ? Maybe go up a few hairs at a time and see if the shimmy starts up again?

On my samples they’ve been ~19.5” in front.

 

[CGH17374]

Extremely light steering, and “not automatically returning to center” are usually indicators of not enough caster, often a side effect of too much lift, or a half-assed attempt at alignment.

I’d suspect worn bushings in the suspension and/or steering for the “shimmy”.

I always find the “trivial 1.5-2 inch lift” in the front amusing, because on the 100 series 2” seems to be on the ragged edge of reason.

Most all of my bushings were replaced when I installed the rear coils but I’ll take a look at the remaining few I didn’t change out. Also I’ll look into a different shop to complete my alignment this time. Thank you jLB.

 

[213374U]

Had the same and after replacing many bushings and ball joints it ultimately came down to alignment. Took it in, toe on the right side was way out of spec, once done the shimmy/vibration was mostly gone and steering was a bit more firm. I have about 1.5-2" of rake unloaded but would have to verify exact measurements. Loaded down for a trip I'm closer to .5" of rake and steering/handling feel great. Only harshness in the ride now is due to the 33" KM3's.

 

[CGH17374]

My thought is that if the shimmy is gone and it's driving alright, just deal with a little stink bug look. Once you load some gear in the rear will settle down a bit.

Is 19.25" lower than factory? I thought 19-19.5 was about right ? Maybe go up a few hairs at a time and see if the shimmy starts up again?

Right now this is my best plan. I do have a little more stink bug than I wanted but it’s not terrible. From what I’ve read factory rake is .75 inches with the front at 19.75 inches and the rear at 20.5 inches. I’m currently in the process of making small adjustments to the TB’s as I try and find the sweet spot between lift and proper steering dynamics. Thank you NXP.