Using a level on rims and tape measure to get rear wheels at an upright angle. According to shop manual they can be + or - 1/2 inch. When vette is jacked up, I'm adjusting wheels on the inboard side of the strut rods looking at a notched shim 3/4 bolt adjuster. (Is this making sense?) How does one know when proper adjustment is reached? Any help would help. Thanks, L8TER, Paul.

 

The tech at the alignment shop I worked with when I have done rear end work sayd the only way you can accurately set trailing arms toe and camber is to have the suspension "loaded" or sitting on the wheels. I set up the initial toe and camber with a level and string and it was close but not right on to mayb eprevent wear. The camber will affect the cornoring of the vette.

 

Here's what I did: The GM assembly manual says 1 - 1 1/2 deg. Negative camber. (top leaning in) They handle great this way but if you are more into how the tires wear, Only go about 1/2 deg. negative. I took a carpenters level with two bubbles and cut it so it would fit the rim edges between the tire without touching the tire. I used swinging angle finder and attached it to the level with two sided tape. I shimmed the level up on the bench until the angle read 1 deg. and then put a mark at each end of the horizontal bubble which is now off center. Now I got four 12"squares of teflon sheet about 1/16" thick. I put a wad of grease between two sheets (so I had two sets) Now I put them on ramps where the wheels will be and backed the car onto the ramps. Now when you move the adjuster, the "plates" will allow the wheel and tire to slide around pretty easy. You can use the same set-up to do front ends also. Setting the toe is easy to do with a set of trammel points on an alunimum square tube. You cannot do rear toe on the ramps because the load needs to be going forward. It is one of those thing you CAN do if you can't find a shop that will do it. I'm a believer in the saying that if you want something done right, do it yourself. :yesnod:


[Modified by silvervetteman, 9:41 AM 3/30/2002]

 

silvervetteman,
GM's 1" to 1.5" neg. camber seems like alot. Mine had 1/2" neg. and I didn't like the suqatting look. I understand your concept-invention for the two poly sheets greased togeather. Maybe you should file that with the US Patent office!! :yesnod: Here's another question for ya..... Do the marks on the strut rod adjusters mean a unit of certain measurement?

 

The 1 - 1 1/2 deg. is in the factory assembly manual or AIM. All other specs. are more conservative. Go figure!! The marking on the bolts may be a guide used at the assembly plant with some sort of fixture. I really like the way my car handles with 1 deg. negative camber.

 

silvervetteman....Can deg. be measured in inches?? Is that a dumb question?? :eek: Thanks, L8TER, Paul.


[Modified by Vettesic, 11:43 AM 3/30/2002]

 

I cut a piece of 2x4 15 inches long ( finished 2x4 is very even in size ) and put the 2x4 against the rim and my level against the 2x4. Over the 15 inch span 1 degree is.261825973 inches or about 1\4" per degree--1\8" per 1\2 dgree.
bob

 

Vettesic -- you can get close to the correct rear camber in your driveway using a level on the tire rim. At that point, you should make an appointment and take her to an alignment shop. I've seen drive way alignments which looked good but ate up rear tires in a heart beat.
:)

 

Camber is easy to see with the eye. Toe in or out is not easy to see. incorrect toe wil eat tires. Camber will wear tire much more slowly. Even the old VW's with lot's of camber in the rear did not wear tires as bad as you might expect... I did an entire car at home after a suspension rebuild,including ball joints and took it to a shop just to make sure. The first place (3 miles away) told me I needed ball joints. Needless to say I went to another place. They put it on the alignment rack and the guy asked who did the last alignment. He said it was almost perfect except for a slight castor adjustment on one side. If you know a good trustworthy shop, fine. Just keep in mind that not all shops know what they are doing when it comes to "low tech"corvettes. :D


[Modified by silvervetteman, 1:10 PM 3/30/2002]

 

As far as I know the alignment specs changed over the years.
I have the 1980 spec in the tech section at my page.
The camber is specified to 0.7 +-0.50, however no measuring units are given. (it's stated 0 degrees for the toe-in)

Vettesic: I'm also confused, some of the data is specified in degrees, others in inches.
How are the inches data meant to be understood??

 

Camber and castor are usually measured in degrees and toe is usually measured in inches. That would be for cars sold in America. :confused:

 

I still dont get it....:confused:
How are f.ex. 1inch toe-in meant to be understood?

 

1\8" toe in means the front of the tire ( or what ever point has been designated ) is 1\8" narrower than the back. I think that is why even american cars are now done in degrees as a degree is a degree no matter what point you choose and the inch has to have a reference. I hope this might help.
bob

 

Ever done the carpenter square thing? Stop your vette on a flat part of the garage floor, I usually use the area under the garage door. Place the long side of the square against the tire and the short side on the floor. Using drill bits, measure the gap at the 14inch mark. I don't have the measurement/degrees info in the house with me right now, but if anyone is interested I'll get it. I've had good sucess with this method, but the floor needs to be flat. If it isn't then document the difference when you take it in for alignment and then always use that spot on the floor for your adjustments.

 

Bob, ok, the above is basically what I had done. Your measurements for deg. to inches gives, me something to go by. Now, according to GM's specs, 1 - 1.5 deg. neg. rear camber converted in inches should be 1/4" to 1/2" ? Am I getting it?

Racer, With your method, what size bit are we talkin?


[Modified by Vettesic, 7:59 AM 3/31/2002]

 

I mis-spoke in my earlier post. It's a framing square not a carpenters square. The gap/angle info is as follows:

GAP CAMBER ANGLE DEGREES
0 0
1/16" 1/4
1/8" 1/2
3/16" 3/4
1/4" 1
5/16" 1 1/4
3/8" 1 1/2
7/16" 1 3/4
1/2" 2

Basicly every 1/4" is a degree

 

Perfect!! Thank You!! L8TER, Paul.

 

Bob, ok, the above is basically what I had done. Your measurements for deg. to inches gives, me something to go by. Now, according to GM's specs, 1 - 1.5 deg. neg. rear camber converted in inches should be 1/4" to 1/2" ? Am I getting it?
I think you are getting it--it would be 1/4-3/8"--I set my 77 at 1/2 degree or 1/8" and a lot of that is I don't like to look at it and see the wheels not vertical. Just my preference. If you have a trig calculator, you punch in the degree's you want x TAN x the distance ( span you are using ) and you have the answer.
bob


[Modified by bob, 8:37 AM 3/31/2002]