Caster

[PlumCrazy]

I am making some extended radius arms to go with my 4 inch lift. My question is, Where do I measure the caster from? Am I basically setting the pinion angle? Should the axle beam lean forward or be 100% vertical? I know the rear pinion is set at 6 or 6.5 degrees, but the front shaft is shorter, so should the pinion angle be a little more aggresive?

-plumcrazy

 

[4x4junkie]

The axle beam should be dead-vertical (or horizontal if you're measuring it right where the radius arm attaches). This should put you right around 5° caster at the wheel when using a 0° offset bushing.

 

[PickupMan04 FX4 L2]

Damn, i thought you were talking about caster oil..

 

[4x4junkie]

Damn, i thought you were talking about caster oil..

I believe that would be Castor oil

 

[PlumCrazy]

The truck has 2 degree bushings. So I want the beam to 100% vertical, if the beam leans foward a little will it mess with anythng other than curving the coil spring a little?

 

[crawlin91]

info in this thread
http://www.therangerstation.com/forums/showthread.php?t=34439

 

[4x4junkie]

The truck has 2 degree bushings. So I want the beam to 100% vertical, if the beam leans foward a little will it mess with anythng other than curving the coil spring a little?

It could cause the caster to be incorrect (or cause it to be maxed out one way or the other). If you're setting this up from scratch, I would do it so you have 4-5° caster using a 0° bushing (or with the bushing zeroed out for caster).

 

[AllanD]

Not enough caster will lead to a truck that "Wanders"

Uneven caster (side to side) is the most common cause of a truck that "pulls"

I purposely put an STX drop radius arm bracket set on my truck to INCREASE the caster as much as possible.

If your truck spends a lot of time at highway speeds on the interstate
the more caster you can get the better.

Caster helps the vehicle to track straight.

Caster also increases "road feel" and the tendency for the steering
to return to center when you are comming out of a turn.

On my truck when cornering hard with a bit of oversteer I can "unload" the suspension by momentarily releasing the steering wheel and letting the steering return (pretty agressively) to "Center"

I NEVER have to wonder where "center" actually is, because it takes some force to have it anywhere other than center.

Makes it real easy to keep it going straight on those long lonely roads.

Oddly it makes it more fun in the twisties too, because you turn into the turn but it "un turns" itself.

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