Model 'A' Ford Front Wheel Alignment
The Ford Service Bulletins are available in an undersized book form. Unfortunately the monthly cover pages were omitted to conserve space, but all the other pages are reprinted in their entirety. A full sized version of the Ford Service Bulletins for the Model A years is once again being reproduced and I highly recommend it over the undersized version.
The bulletin states "Pull car forward at least three feet before placing gage in position. Place gage between front wheels with ends of gage bearing against the tires and both pendant chains (6" long) barely touching the floor."
"Test for play in bushings by pressing outward on the front of both front wheels at the same time."
"Set the scale on the gage so that the pointer registers at zero; then with the gage still in place, move car forward until gage is brought to a position back of the axle with both pendant chains barely touching the floor. The pointer will now register the exact amount of toe-in." April 1928
Additional Notes:
- With the chains touching the floor, the gage is 6" above the floor.
- No Model A wheels run perfectly true and as such have some degree of wobble. With the original gage positioned and remaining in place throughout the process as specified, any wobble in the wheels is compensated for completely.
- If it is desired to service the tie rod (spindle connecting rod) ends without moving the brake housing plates, in most cases it's possible to access the end plugs by turning the steering all the way to one side and access the plug on the opposite side. As a last resort loosen the clamp bolts and unscrew the rod. Both ends should release at approximately the same time. The rod ends may then be turned for access to the end plug. In either case the toe-in will require readjustment. When reinstalling, be sure the clamp bolts face the rear of the car, and that both ends engage the rod at nearly the same time.
How To Apply This Information Today
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The wheel image to the left indicates some of the possible
measuring points for setting the toe-in. Points "A", are the points used
following the original method and measurement (from 6" above the
floor). The original specification of 1/16" calculates to .194 degrees
toe-in.
Using measuring points further from the center (spindle), slightly
increases the required toe-in measurement to maintain the same degree of
toe-in. Using measuring points "B" or "C" increases the toe-in
measurement by 1/50". Using measuring points "D" increases the
measurement by 1/27". While the difference seems minimal, it's important
to keep in mind when making the final check.
Points "C" and "D" are for measuring at the tread surface (see "Suggestions" below) |
Suggestions
The original method is the simplest and most accurate (short of more modern alignment equipment) but not everyone has an appropriate gage. Alternatives include multiple checks to average the different readings obtained from different positions of the tires, or raising the tires off the floor and applying a thin chalk line on the tread surface while slowly turning the wheel and using these lines for measuring points. The latter also compensates for wobble as it applies to measuring and setting the toe-in.
Measuring points "B" and "D" (above) are potentially the best points to use but require a device with angled or offset ends that must NOT flex or distort during the process. Measuring points "A" and "C" are the simplest due to the easy access.
Be sure to drive the car forward a few feet before the first and final checks. The toe-in may be slightly increased (maybe an additional 1/16") to add stability to a loose front end until proper repairs can be made. However, this will increase the wear on the front tires.
Source: http://www.abarnyard.com/workshop/align.htm
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