4WD Front End Alignment

fordsucks2 · May 14, 2006

I am working on my 2000 Chevrolet Silverado, 5.3L, Z-71 Ext. Cab Pickup and I can't get it properly aligned. I am using a computerized 4-wheel alignment rack at my school and I swear I spent 5 hours trying to align the thing and no luck...I did get it where I could drive home without the tires turning bald on me.

We've studied eccentric cams in the classroom but this is the first time I've ever dealt with one (I like the shim type better). If GM switched from shim type to eccentrics, they'd do it because it's easier....right? Anyways, On my truck there are two cams on each end where the control arm connects to the frame. Is the first one for caster and the second one for camber? When I have the front end raised and I finally get everything in the red in the green and then lower it again, do a caster sweep, everything is off and I mean way off.

It's like a riddle wrapped inside an enigma!

Sorry...I'm a little disgusted

Basically could you explain how to properly adjust camber, caster and toe on my truck.

Much Thanks

fordsucks2 · May 16, 2006

Today at school, I successfully aligned the front end on my truck

On the way home, I was cruising on the highway going about 60-65 mph with a grin on my face when this deer just strolls out into the middle of the road, I just blinked and there it was at my hood. (could've been a cow, don't know, happened so fast and I couldn't tell from the roadkill). I have a grill guard on my pickup so when I hit the beast it went under the chassis and bent the hell out of one of the torsion bars, I mean the thing looks like a bent straw. After I stomped my foot and said some choice words, I drove on home and it rode like a ford with a screwed up I-beam.

After jacking it up, I figured out how to remove the torsion bar, got a another from the junk yard but I'm not sure how to properly adjust it. Do I have to do it on the alignment rack or is there some type of special procedure. I've read that this will drastically affect alignment and drivability so I just wanted to be sure.

Thanks in Advance

mmmikkke · May 16, 2006

You probably should have your frame checked out. Could be bent, if there was enough force to bend your torsion bar.

ChevyTech007 · May 14, 2006

What front end machine are you using? Is it laser or camera?

fordsucks2 · May 14, 2006

What front end machine are you using? Is it laser or camera?

<{POST_SNAPBACK}>

I can't remember the brand name but it's laser guided

mmmikkke · May 14, 2006

You have to think in terms of which direction the upper ball joint is moving relative to the lower ball joint.

If it's moving forward (relative to the truck) you're decreasing caster. If it's moving backward, you're increasing caster.

If it's moving outboard, you're increasing camber. If it's moving inboard, you're decreasing camber.

Not sure if I have the + and - right, but I think you get the idea.

Do one side at a time. Note that each eccentric has a bottom and a top position, and it might be possible to go clockwise OR counterclockwise when travelling from bottom to top. Or there might be a stop so you can only travel one way. If there's no stop, then you have to use your head. Make both eccentrics work the same way, if one's gone clockwise on its way from bottom to top, the other one should be the same. That way, when you get to the camber adjustment below, turning both eccentrics the same way will get you the desired results.

Start by setting caster. Do whatever you have to to get the caster right. Then, for setting the camber, make equal adjustments to each eccentric, so that caster is not affected during the camber adjustment.

After all that's done on both sides, then set steering wheel center and tow-in.

ChevyTech007 · May 17, 2006

You have to adjust the Z height. Can't really explain without pictures. You can get pretty close buy just measuring from the top of the wheel well to the ground on each side. Adjust the one you replaced until it measures the same. You will have to align again.