Really basic caster, camber, toe clarification

[Tudorwagon]

Before I start in on doing some alignment work (see my other thread) I thought I'd better get absolutely clear on caster, camber and toe. I did a search but didn't find much info which clearly defined each setting in layman's terms. Correct me if I'm wrong on the following:

Negative caster = the top of the line intersecting the upper and lower ball joints is in front of the bottom of the same line
Positive caster = the top of the line intersecting the upper and lower ball joints is behind of the bottom of the same line

Negative camber = the top of the tire leans in farther than the bottom of the tire
Positive camber = the top of the tire leans out farther than the bottom of the tire

(These are pretty obvious but I figure I should cover all three settings)
Toe-in = the front of the tires are closer together than the rear of the tires
Toe-out = the front of the tires are farther apart than the rear of the tires

TIA

[DusterRT]

Negative caster = the top of the line intersecting the upper and lower ball joints is in front of the bottom of the same line
Positive caster = the top of the line intersecting the upper and lower ball joints is behind of the bottom of the same line


Yes. I think I get what you're saying at least. With positive caster, the top of the line passing through the UBJ/LBJ would lean towards the middle of the car; negative towards the front. You're right with everything else. Let us know how the home alignment stuff works out, I've been looking at that myself for a while..at $65 a pop, it can get expensive if you change things even infrequently!!

[Tudorwagon]

You know, I typed the caster stuff about three times and I think I had it right the first time. I thought about it too much! So, the correct info is:

Negative caster = the top of the line intersecting the upper and lower ball joints is behind of the bottom of the same line
Positive caster = the top of the line intersecting the upper and lower ball joints is in front of the bottom of the same line

Negative camber = the top of the tire leans in farther than the bottom of the tire
Positive camber = the top of the tire leans out farther than the bottom of the tire

Toe-in = the front of the tires are closer together than the rear of the tires
Toe-out = the front of the tires are farther apart than the rear of the tires

[DusterRT]

Let's see if this works: "/" is the imaginary line passing through the ball joints in the front end of a vehicle.

<front of car> [ / ] <rear of car>

^^^^ This would represent positive caster. ^^^^


<front of car> [ \ ] <rear of car>

^^^^ This would represent negative caster. ^^^^

<front of car> [ | ] <rear of car>

^^^^ This would represent zero caster. ^^^^

[Tudorwagon]

Then I had it right in the first post. Sorry I didn't make it more clear what I was saying, it sounded good in my head!

Thanks.

[DusterRT]

No problem..sometimes things are just hard to convey clearly over the keyboard!

[David Pozzi]

Here are some links
ALIGNMENT HOW TO

http://www.heidts.com/heisinfo.htm
http://www.carcraft.com/editorial/mgarcia_article.jsp?viewtype=text&id=24880

http://www.shallowsky.com/alignment.html

http://www.vtr.org/maintain/diy-alignment.html

http://www.carcraft.com/editorial/mgarcia_article.jsp?viewtype=text&id=24880

http://www.monte-list.nu/tech/boxmesh.shtml STEERING BOX ADJUSTMENT- MANUAL

http://jeffd.50megs.com/Pump_valve_mod_page.htm POWER STEERING VALVES

http://www.ifsja.org/tech/steering/boxadj.shtml STEERING ADJ SAGINAW POWER

http://www.chevyhiperformance.com ARTICLE ARCHIVES ON SUSPENSION

http://www.musclecar-usa.com/carsetup.shtml SUSPENSION TUNING CHARTS

[Tudorwagon]

Thanks for the links David. The Car Craft and VTR links are no longer working (at least they didn't work for me).