Installed 2.5" Cornfed Lift - Re-alignment Results

[imjin]

Here's some data for those getting ready to install a Cornfed 2.5" front lift spacer and a 1.25" rear block. As far as I know, my alignment was in pretty good shape prior to the lift, or at least it felt like it. It's interesting how much out of whack the alignment can get with this small of a lift. It really threw the toe off.

http://www.tundrasolutions.com/photo...cat/500/page/1

[DJ]

Total toe is fine, but caster is really bad. I suggest you read DJ's Alignment Setting Recommendations and then have it aligned again.

[imjin]

Where do the shops get that specified range for total cross caster of -0.5 to 0.5? Was that a Toyota issued spec? I read your link on alignment (DJ's Alignment Setting Recommendations) and have a much better understanding of it, but I know next to nothing about alignment, so forgive my inquiries if they seem challenging... I'm just trying to figure out what's what. When you said in it that the Toyota "in spec" caster value of a 1/2 a degree is unstable, I understand the steering axis could be pitched too far in either direction, but could a lesser caster value be OK in some cases, or is my cross caster value of -0.3 way too low? Should I be able to tell, just by the way the steering feels, if it's pitched too far and the oscillation effect takes place that you mentioned?

[DJ]

Originally Posted by imjin

Where do the shops get that specified range for total cross caster of -0.5 to 0.5? Was that a Toyota issued spec? I read your link on alignment (DJ's Alignment Setting Recommendations) and have a much better understanding of it, but I know next to nothing about alignment, so forgive my inquiries if they seem challenging... I'm just trying to figure out what's what. When you said in it that the Toyota "in spec" caster value of a 1/2 a degree is unstable, I understand the steering axis could be pitched too far in either direction, but could a lesser caster value be OK in some cases, or is my cross caster value of -0.3 way too low? Should I be able to tell, just by the way the steering feels, if it's pitched too far and the oscillation effect takes place that you mentioned?

The Toyota Repair Manual lists specs for camber, caster, SAI, and total toe. It does not list a spec for cross caster.

The problem with your alignment is not cross caster (i.e. the difference between left and right caster), it is low caster at both the left and right wheels.

There is no way to predict whether or not your truck will vibrate due to steering instability with the caster settings it now has. What can be predicted is that it is much more likely to vibrate with its low caster settings than it would if caster were higher, and it is likely to be sensitive to ruts in the road, to wind drift, and to "wander", meaning you have to pay careful attention just to keep it going straight down the road.

I suspect you would notice the problem quite well if you had it aligned to my specs. Been there, done that.

[imjin]

Ah, I see now. Thanks for the explanation.