Understanding 100 Series Caster Alignment (set caster at-home, DIY) (4 Viewers)

[cruiserpatch]

Had a buddy ask me how to max his caster out before taking it to the dealer for setting toe.

Figured I'd take the opportunity to share my notes and a few things I've learned over the years.

Cruiser Patch YouTube video: how to align a 100 Series Toyota Land Cruiser/Lexus LX470

Introduction

Most IFS vehicles with a double-wishbone suspension have adjustable cams located on the lower control arms. The 100 is unique in this regard because the Torsion Bars (springs) are connected to the LCAs. The rotary tension from the TBs forced Toyota to put the alignment cams on the UCAs which reverses typical rules of thumb for alignments, in particular related to setting caster.

For example, on the 200 series one would rotate the cams to push the spindle away from the firewall to increase camber (again, on the LCAs). On the 100 series, one must pull the spindle/knuckle towards the firewall to increase caster. This can be done in two ways:

1. Bolt-on aftermarket UCAs (with increased caster*)
2. Adjusting the alignment cams

*Not all aftermarket UCAs increase caster - Total Chaos, to name one such brand, left me dissatisfied with my caster numbers even completely maxed out (about 1 degree with 1.5" lift)

Above: Alignment on 1999 Lexus LX470 with Total Chaos UCAs and 1.5" lift

Hoser thread "post-lift alignment readings"



How-to w/ pictures

The easiest way to achieve higher caster numbers on a 100 series is also FREE!

Above: SPC UCA (RH side) with forward cam pushed outboard and rear cam pulled inboard

1. Push the forward cam outboard by rotating the assembly clockwise (viewed from rear).
2. Pull the rear cam inboard by rotating the assembly counter-clockwise (viewed from rear).
3. Double-check your ride height (as this affects alignment) and take the vehicle to get an alignment. Ask the tech to set Toe only.

Above: rear cam rotated counter-clockwise to achieve maximum caster. Couple this with SPC aftermarket UCAs for even better readings.

Above: alignment numbers 1999 Lexus LX470 on 1.5" lift with SPC UCAs


Conclusions

Camber is bound to 'be what it will be' in this scenario but it is possible to achieve decent tire wear even with maxed out caster.
Caster, camber, and toe are always in relationship with each other so its up to you to decide exactly what to emphasize and how to achieve it.
For my needs, I prefer best handling off-road with good on-road manners as well. I go through tires pretty quickly so minimal camber is not high up on my priorities list

I opted for the SPC uppers for one reason above anything: ease of trail repairs.
If I wind up needing to replace a ball joint in the field I would much rather be able to do so with hand tools and 5 minutes of my time than have to rent a ball joint press etc.
I run mine in position 'B' for approximately 1.75 degrees of additional caster compared to stock arms.

Above: SPC adjustable UBJs

 

[offoradjunkie]

Nice writeup, Patch. Thank you. One question that is somewhat unrelated - I had to max out caster with my SPC Uppers due to having bent spindles.
Would you ever gusset yours? Seems like every time I get it aligned I bend my spindle more...

 

[cruiserpatch]

Would you ever gusset yours? Seems like every time I get it aligned I bend my spindle more...

I've bent three or four spindles now over the years. I recently bent my RH spindle (see alignment specs below before vs after) which finally convinced me to work on a method of bracing/gusseting them.

For now I'm still in R&D phase but once I have a working prototype I'll test it out and bring it into production if it works.

The trick will be strength without compromising access to the UBJ nut.

Above: March 7, 2025 (before)

Above: July 11, 2025 (after)

 

[Goslow]

Thank you for a most informative post. I’ve had an ‘01 LX 470 for 3 1/2 years and it is my first IFS truck. I’ve wheeled with live axle trucks for 40 years and I have a lot to learn about IFS. So here’s my dumb sounding question.
Why would a UCA ball joint need to be replaced on the trail instead of waiting until the trail ride is over? Is it the weakest component in the IFS suspension and does it break often?