After driving Miss Purdy a few times I decided to make another appointment back at the alignment shop and have the toe-in checked again. Although they assured me on the phone that everything had been adjusted properly according to their spec's, she just didn't feel as nimble as it did before the alignment.
Since it is quite a drive into the city I decided to at least try to make a basic toe-in check at home. Has anyone looked at buying one of the "Do It Yourself" Lazar type alignment gizmos ? One manufacturer had a reasonable selling price but wanted an additional $100/month contract for software support to keep their top secret Trapozodial-Hyper-Bolific-Transendental software package current ? I'm sure owning one of these things would be nice but it seems to be over kill for most of my home projects and way too complicated for my needs. When I replace front end components I normally just use some very basic old school methods that will get things close enough to make it to an alignment rack without scrubbing the front tires off. I took a couple of photos to give you a general idea of the toe-in set up. Camber and caster are another animal all together but can also be closely estimated.
My rough toe-in procedure is to first find a flat level cement slab to park the car on and check that all the tire pressures are correct. Center the steering wheel and install the specialty "Nose Cone" centering bolt into the rack and pinion housing. Next, set up 4 heavy jack stands - each one just past the corner of the car and run a tight string front to back down the length of each side. Set the string height across the middle of each rim so that it is evenly spaced out from the front/rear rim center caps exactly 1 inch. This should set each string square to the side of the car. I then carefully measure the distance from the front and rear edge/lip of each front rim to the string. For this measurement I switch to centimeters on my tape measure for a finer hash mark and more precise (for me easier to see) reading. Just as I suspected I found that my toe-in was way off. I placed masking tape with red marks around each tie rod so I could keep track of the direction and how much they were rotated. As I adjust the tie rods 1/2 rotation at a time, I make sure to roll the car forward and back a few times to relax the steering and suspension components. I place a chock behind each rear tire so I can return to the same measuring spot after each final roll back. Now that I have a basic idea of what is needed I set a final .2 cm toe-in at each front tire and snugged the tie rod nuts. It's a little difficult to hold the camera steady vertically so you can see the exact measurement and tape measure in the correct place all at the same time. The close up photos of the rim are only of the drivers side with the front edge of the rim showing 3.4 cm and the rear edge of the rim 3.6 cm. The passenger side rim adjustment would be set to the same relationship.
Once I am satisfied with my final toe-in settings, I then make a side to side measurement under the car between the front two tires using the tread as a marker. I use 4 squared off 4" x 4" blocks (2 per wheel) to standardize the height from the ground to my measuring points. Now again using the centimeter scale I have the wife hold one end of the tape measure against the inner edge of a specific vertical groove on the front side of the right tire while I take a reading at the same tread point on the front side of the left tire. Make sure the tape measure rests across the top of the 4" square block on each side to standardize the measuring height. This measurement is repeated on the rear side of the front tires and the two readings compared. As a cross check - Roll the car forward about 1/2 tire rotation and repeat this measurement.
For the side to side measurement across the front of the tires I used the out side large vertical groove. It's showing 159.2 cm. The back side of the front tire using the same grooves for a measurement was 159.4 cm. One point that I should have also mentioned is that when reading across the front and back side of the tires it is at a much lower point (4" from the grd) rather than at the max distance across the middle front and back face of the tires. Since this measurement was 159.2 cm at the front measurement and 159.4 cm at the rear it means that the .2 cm difference indicates a .1 cm toe-in per tire at this location. Still indicating the slight toe-in I'm looking for.
So far I've found that the toe-in was again about the same .2 cm per side using the first method of measurement. After a 10 minute test drive, since the toe-in had not changed I felt that it would be a non-destructive return drive back to the alignment shop.
I am sure a trained alignment tech would find a lot of faults with this process and I realize it is not very scientific. At best it does not take into account that my cement slab is not calibrated to be flat to the center of the earth,
that the middle position or center of the front and rear wheels may not be square to each other or that my rims may not be perfectly true and/or the tire tread may not have been absolutely centered all the way around the tire. But like I mentioned, all I wanted was a reasonable method to safely get me back to the alignment shop. On a positive note : It turned out that my camber and caster were fine and the toe-in was only off a "Gnats Ass" according to the second alignment tech - I'm not sure how many centimeters are included in a gnats ass .............
Any comments are welcome.
Good Luck, Michael