Caster settings on a SFA Chevy?

[sled_dog]

to be noticeable, I greatly agree it would have to be a big time load, but you also won't really notice a degree or two. Except maybe a slight pull if the load were to one side for some reason.

 

[bernman]

i work at an alignment shop, and it will change, but like monster-man says it depends on wheelbase, amount loaded and how far foward it is loaded.

 

[bernman]

i also assume we are talking about solid axle trucks, so sled-dogs claim of wehicle pull is innacurate, vehicle pull due to caster is caused by an increase or decrease in cross caster, and since solid axles have knuckles permantly attached to each other, the cross caster can never change due to load

 

[sled_dog]

doh, you are right, if everyting is perfect. Have seen rigs break the rosette welds, but that is a whole nother story.

I was thinking of the Dodge Ram we have at school but that is IFS 2wd.

 

[BigCountryx]

According the my 1973 GM Service Manual, and my brother, who's a tire wheel engineer for GM who looked up the spec for a '91, the K10 & K20 Alignment specs which matched the ones in my 73 GM service manual, so 1973-1991 K10 & K20 are as follows:

Caster: +4* Not resettable (well it is sligtly if you use different length schackles)
Camber: +1.5* Not resettable (well it is with the upper ball joint special sleeve or the camber shim between the spindle & knuckle)
Toe: 3/16" (exc K10 w/ Full time 4wd= 0")

Tolerances are as follows:
Service Check:
Caster: +/- 1*
Camber: +/- 3/4*
Toe: +/- 1/8"
Camber (Sdde-to-side): 1*
Caster(Side-to-side): 1*

Service Reset:
Caster: +/- 1/2*
Camber: +/- 1/2*
Toe: +/- 1/16"
Camber(side-to-side): 1/2*
Caster(side to side): 1/2*

(Service check states: Values within these limits should provice a high level of customer satisfaction and shoud not require resetting
Service reset states: Values that the vehicle should be set within if it observed out of the service checking tolerace or if it is being aligned due to replacment components or for any other reasons)

May be a stupid question, but when you say toe is 3/16", that means that the front of the tires should be 3/16" closer together than the rear of the front tires, correct? If this measurement is taken at the tread, wouldn't someone running 31" tires be actually running more toe than someone running 40" tires? If you move farther away from the center axis (the axle) then the measurement would be different for each tire size.

 

[sled_dog]

those are factory specs, what about them do we really stick to besides hopefully camber

 

[bernman]

you are correct bigcountry, but really on a truck with positive camber it shows that around zero toe , actually works out alot better you will see less wear this way, on most of our trucks we will have about .5 to 1 degree of positive camber and thats usually where we like em.