Post Lift Alignment.. Is More Caster Better?

[YFZsandrider]

Lots of threads out there about alignment, but they mainly discuss how to get caster back as close as you can... My question is, how much caster is optimal?

If you're running aftermarket UCA and have a wide range of caster available, what's a good number to shoot for?

I just got my alignment done, and my numbers were 2.25 egrees left and 2.5 degrees right. I had the alignment tech set it there based on a general consensus of things I've read. The alignment drives pretty nice, with the exception that it seems kinda vague in the center of the wheel. It doesn't seem to return to center very strong. And on some highways, I'm constantly making little corrections in the wheel toward center.

If I can reach 3 degrees or slightly over in caster, is there any reason not to?


Edit- my setup is the following... Allpro UCA, brand new Whiteline LCA bushings, Toyota OEM lower ball joints and outer tie rod ends

 

[JRZEE2000TR4LTD]

Lots of threads out there about alignment, but they mainly discuss how to get caster back as close as you can... My question is, how much caster is optimal?

If you're running aftermarket UCA and have a wide range of caster available, what's a good number to shoot for?

I just got my alignment done, and my numbers were 2.25 egrees left and 2.5 degrees right. I had the alignment tech set it there based on a general consensus of things I've read. The alignment drives pretty nice, with the exception that it seems kinda vague in the center of the wheel. It doesn't seem to return to center very strong. And on some highways, I'm constantly making little corrections in the wheel toward center.

If I can reach 3 degrees or slightly over in caster, is there any reason not to?

Spec is 1.7 to 3.4. No more than .5 difference side to side (cross-caster) More than this and you could cause you to pull to the side with the least amount of caster. More is better. It helps with the issues you're experiencing. Wandering steering and return to center steering.
A perfect caster setting would be 3.4 on the right and 3.0 on the left. This will help compensate for road crown.

 

[JayRolla]

Lots of threads out there about alignment, but they mainly discuss how to get caster back as close as you can... My question is, how much caster is optimal?

If you're running aftermarket UCA and have a wide range of caster available, what's a good number to shoot for?

I just got my alignment done, and my numbers were 2.25 egrees left and 2.5 degrees right. I had the alignment tech set it there based on a general consensus of things I've read. The alignment drives pretty nice, with the exception that it seems kinda vague in the center of the wheel. It doesn't seem to return to center very strong. And on some highways, I'm constantly making little corrections in the wheel toward center.

If I can reach 3 degrees or slightly over in caster, is there any reason not to?

The issue you are feeling is most likely a worn steering part than the alignment. I have ran 0-5* caster with not much of a difference in driving feel. I have 1.5* caster at the moment and it returns to center just fine.

WHen I had the issue you are experiencing it ended up being a loose inner tie rod end.

 

[YFZsandrider]

The issue you are feeling is most likely a worn steering part than the alignment. I have ran 0-5* caster with not much of a difference in driving feel. I have 1.5* caster at the moment and it returns to center just fine.

WHen I had the issue you are experiencing it ended up being a loose inner tie rod end.

Not much of a difference between 0 and 5 degrees of caster?! Sounds a little hard to believe...

 

[JayRolla]

Not much of a difference between 0 and 5 degrees of caster?! Sounds a little hard to believe...

I know right?? I had an entire thread about it. I was able to get 5* caster with my SPC's at max caster setting and still had major pinchweld rub. I then flipped the arms to the forward most location which brought me to around 1.5* caster. I could not feel any difference in driveability. I was able to completely eliminate all pinchweld rub.

I drove for a long time at both 1.5* and 5* and could not notice anything different. If you are able to get 1* or more there is very little change.

 

[fourfive]

Not much of a difference between 0 and 5 degrees of caster?! Sounds a little hard to believe...

I had a similar experience that JayRolla is talking about except my caster ranged from 1.5 to 3.5 & I didn't notice much of a difference in handling and my steering wheel would re-center the same. I have SPC UCAs and also chose to go with less caster to avoid the pinchweld rub.

 

[YFZsandrider]

I had a similar experience that JayRolla is talking about except my caster ranged from 1.5 to 3.5 & I didn't notice much of a difference in handling and my steering wheel would re-center the same. I have SPC UCAs and also chose to go with less caster to avoid the pinchweld rub.

Ok, but.... when you say "less caster to avoid pinch weld rub," you're dealing with spc light racing arms whereby you're adjusting the caster (atleast initially) via the plate at the ball joint. I have Allpro uniball UCAs... so my adjustment for any caster would come from moving the lower control arms foreward, and would actually improve clearance of the pinchweld.

 

[JRZEE2000TR4LTD]

Ok, but.... when you say "less caster to avoid pinch weld rub," you're dealing with spc light racing arms whereby you're adjusting the caster (atleast initially) via the plate at the ball joint. I have Allpro uniball UCAs... so my adjustment for any caster would come from moving the lower control arms foreward, and would actually improve clearance of the pinchweld.

You are right. Increasing caster with the SPC arms actually induces rear pinch weld rubbing as it moves the spindle back. The SPC arms have 2 degrees caster built into them at the center setting. I think the All-pros are the same. Then you just adjust the lower cams. Shortening the front cams (turning them in) and lengthening (turning them out) gives max caster. This obviously needs to be done within the camber spec.

 

[fourfive]

Ok, but.... when you say "less caster to avoid pinch weld rub," you're dealing with spc light racing arms whereby you're adjusting the caster (atleast initially) via the plate at the ball joint. I have Allpro uniball UCAs... so my adjustment for any caster would come from moving the lower control arms foreward, and would actually improve clearance of the pinchweld.

Yes, when I was referring to "less caster" for pinchweld clearance, it was regarding the SPC uca adjustment.

 

[IBallEngineer]

I've seen Tacomas and Tundras have 1 degree of cross Caster do a stage dive to the lower side at 60 MPH. And I have seen a car with 3/4" of set back on one side, 8 degrees(yes 8) of cross Caster and drive straight. It did rub the fender though!

All things being equal, I'm going to run as HIGH positive Caster as I can while keeping Camber. Pinch welds are easy to modify.

 

[JayRolla]

I've seen Tacomas and Tundras have 1 degree of cross Caster do a stage dive to the lower side at 60 MPH. And I have seen a car with 3/4" of set back on one side, 8 degrees(yes 8) of cross Caster and drive straight. It did rub the fender though!

All things being equal, I'm going to run as HIGH positive Caster as I can while keeping Camber. Pinch welds are easy to modify.

It's not just the pinch weld your getting clearance. It clears the entire wheel well. At 5* caster using spc arms I would flex 33"s into the wheel well. Flipping the spc arms forward and maxing lca bolts I got 2*. I completely clear the wheel well in all flex situations. Above poster is running his the same way and it clears his 35s on the road which is pretty impressive.

 

[IBallEngineer]

It's not just the pinch weld your getting clearance. It clears the entire wheel well. At 5* caster using spc arms I would flex 33"s into the wheel well. Flipping the spc arms forward and maxing lca bolts I got 2*. I completely clear the wheel well in all flex situations. Above poster is running his the same way and it clears his 35s on the road which is pretty impressive.

I didn't see tire size on the OP's post, saw the guy with 35's, also has a 2" body lift. Obviously it works for you as is, just saying if I could, I'd keep the caster. Daily driver vs weekend warrior has a lot to do with it too.

 

[YFZsandrider]

I didn't see tire size on the OP's post, saw the guy with 35's, also has a 2" body lift. Obviously it works for you as is, just saying if I could, I'd keep the caster. Daily driver vs weekend warrior has a lot to do with it too.

Right now I'm on 265 75 16 Duratracs, but I'm stepping up to 285s in the next coupe months.

I'll update the original post

 

[JayRolla]

I didn't see tire size on the OP's post, saw the guy with 35's, also has a 2" body lift. Obviously it works for you as is, just saying if I could, I'd keep the caster. Daily driver vs weekend warrior has a lot to do with it too.

The clearance out ways the caster by a long shot. 2* had zero noticeable change going from 5*.

 

[judoant]

Flipping the spc arms forward and maxing lca bolts I got 2*. I completely clear the wheel well in all flex situations.

How exactly is this achieved? What setting would I choose on the UCA? Does this also involve adjusting the lower control arms all the way forward? I am installing SPC UCA's soon to clear oem UCA's and firewall since I recently installed 285's and am now rubbing those areas.

So the final alignment specs should be 0-.2 camber and 2* caster? I too need clearance with the wheels stuffed off roading.

 

[Bdnewyork]

I'll be moving to Wildpeak A/T3W 255/80R17 33's from my Cooper A/TW 265/70R17. I'll be installing SPC UCAs when I do the tire swap and have read a lot here in preparation. My plan, per this thread:

SPC UCA Alignment Sheets

is to start with the G setting on the SPCs and see how that works out.