Maximum Caster?

Can someone tell me the maximum caster possible with a stock suspension? I have heard you can get it close to 4 degrees and others have said you can't get that high with stock control arms without throwing off the camber. Anyone know or have experience with this?

 

Why would you want you castor that high on stock suspension?

Try 3°

 

I believe 3.5 is achievable but every rig is different.

3.5 - 4 is a good target for these trucks ime

 

It's wandering on the highway something fierce. Just going by others experience saying it really helped. I wasn't sure it could be adjusted that far with stock upper and lower control arms.

 

With stock suspension?

 

Yes I believe 3.5 is achievable at stock height with stock arms but again it depends on the truck. Each one is a little different.

Anywhere from 3 to 3.5 degrees should solve that wandering problem these things have.

 

https://www.4runners.com/threads/5th-gen-4runner-alignment.13078/

There are some people in this thread who are lifted 2" in the front and still able to achieve 3.5 degrees of caster with stock UCA's

Should be even more achievable at stock height

 

Can I ask a dumb question

Positive castor on the UCA moves the tire back.
Positive castor on the LCA moves the tire forward.

is my 3.4-3.7° castor reading a combination of SPC UCA and factory LCA?
I believe want my tire slightly more forward away from the bmc on my next alignment, so that’s the LCA going more positive?

https://www.tacomaworld.com/threads/adjusting-caster-on-total-chaos-ucas.618900/#post-23283320

 

The little diagram on the report says it all. Caster is a single angle that can be changed by moving either end (or both ends) of the axis that defines it. It might be better to rephrase the two sentences as:

1. Backward movement on the UCA increases positive caster
2. Forward movement on the LCA increases positive caster

 

Op, if your going in for an alignment shoot for 3° or slightly above. It should solve your wandering problem.

Also, it could be a tire related issue. Rotate and make sure the pressure is equal. Pressure to high or to low can cause wandering as well.

 

Thanks for the this
I feel like I gained more knowledge, and more confusion at the same time HAHA

I have never adjusted or watched LCA’s adjusted before, but I did dip my feet in UCA’s when I replaced SPC balljoints to sealed units. However I just matched the previous star plate alignment so I didn’t change or learn much.

My brain tells me forward movement not backward on the UCA increases positive castor/angles tire backward? But I’m prolly thinking about it incorrectly so don’t listen to me.

My question should be:
“SPC’s are adjustable” so what’s that mean;
Is it possible to slide the tire forward while remaining on the same ° angle I’m at?
I don’t want my tire further back, UCA tilted forward brings back the tire beneath it. So can SPC’s slide forward and back inside a channel of some sort and not change angle? Hence why I asked if “sliding” LCA forward can be how I move tire forward now and leave UCA alone.
In other words when I move LCA and tire forward, can I bring the UCA with it on the same angle. Or, does everytime one adjusts the LCA forward, it in turn pivots my UCA axis negative/back.

try to make sense of that word salad^
Sorry for thread jacking and thank you, because I find this more educational than YouTube vids

 

Had it aligned. They got 3.4 degrees of positive caster. Way too windy to tell if it helped but I will report back once conditions allow testing.

 

My experience was that you can’t get it that high on a 2” lift and stock UCAs without throwing off the camber. I tried at three different shops.

Did you succeed at this with a lift or without?

my car drives great, but my caster isn’t as high as 3°. Probably 1° or so.

 

OP's on stock suspension. He was able to achieve 3.4 degrees

 

I was told I couldn't get more than 2.5 or so with stock suspension, was not the case. Not sure how a 2" lift impacts that.

 

3° on stock should be doable. Sounds like you achieved it.