Rudimentary C2 Toe-in Adjustment

[Gary B.]

Thanks,


Gary

[Mark F.]

Re: Rudimentary C2 Toe-in Adjustment

Hi Gary,

Assembly Plant alignment pits I worked in (1977-1981 measuring employee carbon monoxide exposure levels) used dynamic roll alignment equipment near the end of the line. Cars were fully assembled and driven onto the alignment station rollers. The rollers would be activated and the front tires would spin at a pretty good clip (can't remember mph) while the employee made the adjustments.

All of this was mechanical equipment (no lasers) with vertical "feeler rollers" that came in horizontally to just barely touch the fore and aft sidewalls of the front tires as they were spinning. These feelers were mechanically attached to a huge dial indicator - easily visible from the pit - which allowed for very accurate (and quick) adjustment precision.

As you know, alignment shops today use similar concepts - except most are not dynamic (front wheels are static) - and the measurements are usually made with lasers.

So, my guess is - and this is a GUESS the toe-in measurements were referenced (at least back then) roughly to the center of the tire sidewall (not all the way out to the tread). Don't know if this helps or not...

[Gary B.]

[Tom E.]

Re: Rudimentary C2 Toe-in Adjustment

What has worked for me over the years is the string method. I like the yellow nylon line brick masons use and can be found at most home improvement stores. Tie the line off at the centerline of the rear wheel hub and pull all the way past the front hub. Under light tension the string should touch evenly both front and rear of both hubs. If you want a little bit of toe then leave an 1/8” gap. This will get you close enough to drive the car to an alignment shop.
Tom

[Gary B.]

[Robert W.]

Re: Rudimentary C2 Toe-in Adjustment

That's exactly what I did too. At the alignment shop (A Corvette restoration shop), the toe in was spot on, but the alignment to the centerline was off a smidge.

[Gary B.]

[John D.]

Re: Rudimentary C2 Toe-in Adjustment

Like gary I also worked on assembly plant alignment equipment mostly in the 2000 time frame. The usual reference used was a master fixture- a rigid metal frame that hung above the stations and was put on each machine (4) once a shift. The rollers would contact a rigid surface and the linear transducers would record a measurement. There was also a rolling master frame on wheels that was much harder to use because it was heavy and hard to roll around.

[Gary B.]

Re: Rudimentary C2 Toe-in Adjustment

[Robert K.]

Re: Rudimentary C2 Toe-in Adjustment

Gary,
Any chance you could send a picture showing the technique with the string "installed"?

Thanks,

Bob

[Gary B.]

[Robert K.]

Re: Rudimentary C2 Toe-in Adjustment

Gary,

Thanks, that explains it! I was just wondering where you tied it off on the rear hub...... I assume that it was tied off on the stud as close to the rear caliper as possible, i.e., the string touched the rear caliper when you stretched it out towards the front, right?

Thanks again,

Bob

[Gary B.]

[Tom E.]

Re: Rudimentary C2 Toe-in Adjustment

Gary,
Glad it helped! After all the suspension is done and the car is sitting on tires you can check it one more time. I tie off at the front sway bar and pull from front to back across the centerline of the tire sidewalls and then tie off on the inside of the trailing arm keeping moderate tension on the line. The forward edge of the rear tires should have equal amount of toe and the front tire should have the same amount of toe. I shim the trailing arms first and then I adjust tie rods until the line is perfectly even and then give it a slight tweak to get a small amount of front toe-in. I did this last September and drove 25 miles to my alignment shop. Car drove true with no pulling or poor handling. Simple yet effective and costs essentially nothing.
Tom

[Robert K.]

Re: Rudimentary C2 Toe-in Adjustment

Gary,

Thanks! Of course, the rotor, not the caliper..... I used the wrong term!

Take care,