solkim

Can anyone tell me the front end alignment specs for a 2000 Express 3500? I bought a Chilton manual, but they don't say. People get scared that it's such a difficult job but it really isn't, can be done with $50 in tools if you know what you are doing.

Little Bear

All of the GM trucks I have worked on were about the same, Camber 0 +- .5 degrees, Caster +3.75 +- 1.0 degree and if I remember right cross caster can't be more than 1 degree. Toe in 0 to 1/8 inch. I agree it's a simple but PITA job, a set of toe in plates make that job a breeze and are something you can make at home.

solkim

Thank you Little Bear. I have some very crude toe plates. Two pieces of vinyl floor tile with some grease in between.

tech2

caster you won't be able to determine but its not a tire wear angle. Adjust camber first and toe last.

ideally, you want to keep the cross caster and cross camber within 0.5 degrees of each other. when the differences get larger than that you get pulls. to large cross caster will turn the wheel on it own.

if the van drives straight now, the camber is in spec and no camber wear is detected on the tires...just adjust the toe. set tire pressures, perform a susension check and replace any worn parts before you begin.

solkim

I have adjusted caster in my 55 chevy with no problem. Factory was only 1° +-1/2. (it was less and they upped it to that for power steering) I now have about 5° and she goes straight down the highway and the wheel now returns to almost center as I let go out of a corner. Handles much better too. I use a cheap bubble caster/camber tool. Extra couple tiles on one side so it's level. Turn the wheel 20° right and 20° left...

tech2

I have seen the caster/camber tool but how does the tool measure caster? where would you mount it on a sla suspension set up on a g van? you would have to take the tire off to get it on a knuckle. the shape of the knuckle may not be the true caster angle anyway.

solkim

It's not so much the actual angle of the castor, but the difference in the angle when turning the steering from 20° left to right. Granted I have not really looked at the van to see where to put it, but a common method, although not the best, is to put it onto jackstands close to the ball joint or as close to the tire as you can get. Then with a magnetic base put the tool on the rotor. The suspension won't be compressed quite as far that way but I'm looking to increase the caster even on both sides, not for a particular number. The tires are wearing even so that isn't a problem, just so I don't screw it up. I just hate the way it wanders left and right down the highway. The other tools if I just spend a little more screw onto the spindle. Then the tire can be on. They did it that way for a long time before they had computerized alignment racks. Old school.

When I did my 55 the first time, I forgot, but I did take it to a shop to have it checked. Of all things, the only thing off was the toe, and the caster numbers of course blew the computers mind so to speak because it had the factory specs. A little a turn of one tie rod and he was done.

tech2

camber measurements thru a 20* sweep is how a alignment machine calculates castor. how would you do the math to get castor readings?

Little Bear

This is the gauge that I use, To use it you turn the wheel being measured out, right wheel full right turn, level and zero the gauge, now turn the wheel full left hand turn, 20 degrees, level the gauge and read the caster measurement. The gauge attaches to the spindle using magnets.

tech2

thanks, I am very interested in getting one of these. As long as you go full turn on each side its accurate or do you need slip plates to measure the degree of turn? What if full turn is greater or lower than 20*?

the alignment machine measures caster at 10* per side and toot at 20* And at full turn ackerman angle would increase toot