The Stovebolt Site Forums The Shop Area General Truck Talk Caster angles ??

Hi, Folks,
I've fiddled around with the front suspension of my '59 Chevy pickup, big-time. Now, I'm wondering what the best caster angle is for the solid axle. I was thinking about 1.5 - 1.75 degrees positive caster, but some of you may have better info on this.
Thanks!

To get the best response, you are going to have to explain what you have changed in the suspension.

Is this a 1/2 ton?

1.5 degrees is the spec for 3100/3200, 3 for 3600, 2.25 for 3800. Allow for .5 degree tolorance. More positive caster will make for more stability, but will create more steering effort. Negative caster will make for easier steering, but will not be as stable, especially at higher speeds.

Hey thanks, Guys! Mine is a 1/2 ton 3200 series. I added some high-lift Jeep Rubicon front springs (same width as stock springs), a power steering box, and disc brakes. I had to remove some too-high-angle caster shims because they gave me that 'lurching' sensation every time I turned the steering wheel. Of course, I had to add air-shocks to get the rear end up as high as the front end. I probably gained a total height change of 5 inches or so.
Regards,
AK

Apache Kid,

You have done a lot of stuff to your truck, things that directly effect the steering dynamics. Improper caster usually doesn't result in a lurching action. Keep us posted on the outcome of this.

Stuart

Stuart, I think I know what Apache Kid is talking about. Jeep Cherokee and Wagoneer (the late SFA versions with the coil springs) have a tendacy to do just that, especially on a hard turn. They tend to run with a very deep caster angle, 7 degrees. They will actully hop so bad on some models that they are undrivable. It's worse on the full time 4x4 versions, especially when a stiff shock is installed, but even the 2wd versions will do it. The solution is to reduce the caster angle to 4.5-5.5 degrees.
Something that has me wondering is- Why so high on the suspension? Also, you may reconsider the use of air shocks to get the rear up. They are not designed for that purpose, and may fail prematurly.

Hey, thanks Longbox! I had previously put 6-degree caster shims under the front leaf springs, which turned out to be a big mistake. The stock suspension had only about an inch of upward travel before it hit the stop, so I decided to get some super-duper springs with the 1 3/4 inch width. So I ordered a set of Rubicon leaf springs, installed them, and ended up with the higher lift getting a couple of extra inches. I tried removing a leaf on each side, but that caused a 'sag' I didn't care for.

Hmmm, interesting comment about the 'High-Jacker' air-shocks. I thought the extra lift was their purpose. Another benefit ot a taller frontal height is that it could well accomodate a front solid drive-axle for 4 X 4 mode. Another reason for the higher rear height is that I installed a fuel tank behind the rear axle where the spare used to be and need a certain amount of clearance for it. Also, when I installed the power steering box, I decided to go to 'cross-steering' rather than face probable bump-steer with the shorter drag-link.
Regards,

If you're planning on a 4x4 conversion, I can see the need for the extra hight, sounds like you're just planning ahead. My questioning was more curiosity that anything.
As to the air shocks, the idea is that they're more of a load leveller for when max load is used and the suspension sags. They're only meant as a temporary suspension lift, not so much a permanant thing. I know that guys use them for that, especialy on Mustangs and Camaros, and on a light vehicle, you can get away with it. But I've had to replace plenty of them that blew out from the constant strain for being inflated all the way without a load. It's very rough on them. You might consider an ad a leaf or a similar lift spring on the rear to match the front. But you may still want to hang on to the air shocks, that way if you load it, you're alrady setup.

Hey, thanks Longbox!! I'll have to look into that once I get past all the other stuff I'm currently doing.

Regards