Castor alignment off?

[NathanOfSeattle]

I recently got my front end aligned. I was told by the shop that the castor is off by .2 degrees and is probably because my 4Runner was in a front end accident (which is true from the previous owner). They also said the castor is not adjustment and that a variance of .2 degrees is not noticeable and shouldn't be a concern.

Is this true?

And what exactly is the castor anyway?

 

[jnnla]

Caster is essentially an offset distance forward or backward from the vertical centerline of the wheel. Adjusting caster in front of this vertical axis will cause the wheel to be "pulled" (like a shopping cart) this is "positive caster"...whereas caster in back of this vertical axis will cause the wheel to be "pushed" (like a wheel barrow) - this is "negative caster." There are a lot of really good descriptions all over the web but generally it's desirable to have positive caster so the wheel is "pulled."

As others on the forum have noted, caster is a drivability issue. Too much negative caster can cause the wheels to wander or not "right themselves" to straight after a turn.

It's really up to how you feel your truck drives if .2 degrees is a concern or not. I would think it really wouldn't be a concern at all. My 4runner is lifted and has caster that is a few degrees negative of spec...sitting at just a hair above 0 degrees. I don't really notice any negative effects on drivability...so I wouldn't think .2 degrees out of spec should be a huge deal.

 

[SCRunner12]

Don't worry about it. Your caster isn't off all that much and it's due to your lift not an accident. As jnnla said, it just matters for how your 4runner handles at high speeds. I had negative caster (-.4) for 8 months and it was a pain but livable. The only way to gain more caster now is to get aftermarket UCA's.

 

[NathanOfSeattle]

Ok thanks. It feels fine though I have nothing to compare against. The only way to find out the perfect caster setting for me would be to try it in various settings, which I was told is not possible. They told me the caster is not adjustable on our 4Runners. Thanks! I'll just not worry about it.

 

[Nelsonmd]

Wait, why did his caster change by more than a degree before and after. That doesn't make sense to me...

 

[SCRunner12]

I was told caster is adjusted when you adjust the camber.

 

[Nelsonmd]

I was told caster is adjusted when you adjust the camber.

I don't think it should. Camber is adjusted by moving the LCA mounts inboard/outboard. That should have very minimal effect on caster. I wouldn't think it could drive the caster by an entire degree. I guess it is ok in this case since it moved it towards spec, but it seems odd to me that it would make that big a difference.