Setting caster - different on the left vs right?

[pippinmader]

So I am tired of the pintle hitch post so here is a different type of question. I recently had my Tundra (2007) aligned after lifting it. I talked to the alignment guy (who also owns the shop I went to and maybe used to work for a racing team... maybe) about some of the numbers because I wanted to minimize camber, we got that worked out.

1. He talked about wanting more caster on the passengers size vs drivers side to help counteract the crown in the road. What are you thoughts on that?
2. He also said camber helps your vehicle self center coming out of a corner. I had always heard caster did that but then started to wondering about a combination of caster and camber together making the effective caster angle point slightly in.

[Lars]

Hm. Sounds like caster and camber are getting mixed up. Different camber settings right to left are what compensate for a crowned road. If you can do the proverbial thought experiment (thanks Albert Einstein for describing that concept in one of his writings, I'm serious) visualize a tire that's extremely cambered, and how it wants to roll in an arc rather than straight ahead. The idea is to have the left tire with more negative (top leans to the outside) camber so that tire tries to climb the off axis road surface.

[1968u15]

I have some thoughts on wheel alignment after having done alignments during my time at Ford and Land Rover dealers. A vehicle tends to pull to the side highest camber (positive camber is top of tire out viewed from front) and lowest caster (positive caster is lower ball joint forward of upper viewed from side). These adjustments can be used against each other, but I try not to do that too much. One can get carried away and end up wearing out tires quickly. I prefer to keep camber on road vehicles with independent front suspension slightly negative. In the 0 to -.75 range. That changes a bit based on driving style and tire wear. That's the key thing with camber it can really shorten tire life. As much or perhaps more that toe in/out. Caster has a lot to do with the individual vehicles spec. That said I generally set cast higher on the right side to keep the vehicle from drifting off road crown. I never let a vehicle end up with a net drift to the left. That is a very dangerous situation on a two-lane highway. When tire sizes and wheel sizes are changed then the settings can change a bit. Things like different offsets and wheel spacers really change the dynamic leverage of the steering knuckle. Wheel alignment is always a balancing act. You're always balancing the things you can adjust against the things you can't, like the included angle and Ackerman which are built into the spindle, while still having a road worthy vehicle that won't shuck the tread off your tires.

[pippinmader]

Thanks! This is great information. I ended up bring it back and they basically brought camber as close to 0 as they could (still -.25 top slightly in) while maintaining caster (left: 2.5, right: 3.0). The limiting factor turned out the be the right front because reducing camber also reduces caster when the only adjustment is in the LCA. My whole goal was to stop the fairly aggressive wear on the inside of the tires. The overall result with the old tires on was steering that felt "lighter" and maybe wanted to wander a little more with a little less self centering. Now that the new load range E tires were on it definitely feels more solid again, maybe the shape of the tread and the ruts in the pavement also have some effect.

[1968u15]

Did they use the camber/caster offset upper ball joint sleeve? That really helped my situation, and it is available in different angles. I was able to use a higher number sleeve than needed then clock it so some of adjustment went to caster as well as camber. I know that the spec for camber is actually positive. I noticed the taller tires really didn't care for that. So, as you did, I tried to get as close to zero as possible and settled for slightly negative. It worked for me as well. The live front axle limits what we can do without spinning the inner C. Even then, no way to compete with IFS for adjustability.