Caster Shims on OME Front Springs? (1 Viewer)

[Rigger]

I've got the same OME set-up with no shims. mine is all over the road. i'm guessing tires. what tires are you guys running that allow for comfortable 75-80 mph speeds?? i have 33x12.5's

jeff

I have OME heavy/heavy and I, too, am running 33x12.5's. Since bolting on these fatso tires, my FJ62 has had a tendancy to wander. Friday, I replaced the tierod, the drag ling, and all four ends with brand spanky new factory Toyota stuff. My local Toyota dealer used state-of-the-art alignment gear to line that baby up. He said the caster is spot on factory spec. The new parts improved things, but it's still a bit imprecise, and still has a slight wander.

What's next to check? Steering box?

 

[Rigger]

Here's my junk:

(The boy is my son, he ain't junk. He's cool!)

 

[Sixty's Guy]

I put 3 degree shims in when I put on extended shackles. I took them out when I went back to stock shackles. I had an alignment done and the shop told me the caster was 3 degrees out. So the shims went back in. BTW OME shackles are slightly longer than stock - 10mm longer I think. Not much, but not identical to stock.

 

[lovetoski]

is the nature of a 12.5" tire going to be to "float" a bit on the road? or is there a brand that is pretty true? or do i need to go down to a 10.5" for a good highway speed stability.

Everything else equal, a wider tire will follow the minor variations in the road more readily than a narrower tire.

 

[lovetoski]

My local Toyota dealer used state-of-the-art alignment gear to line that baby up. He said the caster is spot on factory spec. The new parts improved things, but it's still a bit imprecise, and still has a slight wander.

What's next to check? Steering box?

I dug through my Firestone lifetime front end alignment paperwork.

Factory spec is 0.08 - 1.58 degrees of caster.

When I first did my lift, the caster after lift was 0.16 (left) and 0.35( right). This is w/in factory spec, but I didn't like how it handled. Felt loose.

Added 4 degree shims, and got the caster remeasured (since it's free!!) and got 3.63 (left) and 3.91 (right). Obviously the "4 degree" shim is nearer to 3.5, but whatever.

The truck handles great with this much caster. You can feel a very strong return to center, it never wanders, I like it.

For a lifted truck, with bigger tires, the factory spec may not be the right target.

As long as everything is tight, and no worn parts in the steering, I suggest tweaking the caster until you like it. Whatever that number is, it's the right number.

 

[rover67]

I agree, mine ended up with close to 4 degrees. It tracks straight with 35 x 12.50 tires at 90mph.

Need more than factory for those wider tires.

Those shims jack with your DS angle though.

 

[mongoose2231]

how do people get these things to 90 mph? oh, v8's ...hmm