Article 1304 - Rear Axle Housing Alignment Checking Procedure

TSB #87 - March 8, 1968
(1965, 66, 67, 68 Fords Equipped with Demountable Carrier, 1967, 68 Thunderbirds Equipped with Demountable Carrier)


Investigation of rear axle housings returned under warranty as being "out of alignment" has revealed that many of these housings were within Engineering design specifications and were needlessly replaced.

The first step in correcting rear axle housing believed to be out of alignment is checking tire pressures and the rear suspension. Tire pressures should be checked in accordance with the specifications found in Group 3 of the appropriate shop manual. All adjustments should be complete before checking the rear axle housing for alignment. The following in-car procedure has been developed to aid field personnel in determining whether or not rear axle housings are properly aligned.

1. Raise the vehicle on any of the following:
    A. Frame contact hoist
    B. Twin-post hoist
    C. Short jack-stands
When using jack-stands, place them under the axle as close to the trailing arm brackets as possible.

2. Using white chalk, or paint, mark a small area at the center of the tread of each rear tire. Scribe a fine vertical line in the marked area on each rear tire. All measurements in this procedure will be referenced to these two scribe marks.

3. Adjust both wheels so that the scribe marks face the front of the vehicle. Using a tape measure, measure the distance from the scribe mark on one tire to the scribe mark on the opposite tire and record this figure (front reading).
4. Rotate the rear wheels so that the scribe marks are facing the rear of the vehicle, 180° from the original position. Again measure the distance between the scribe marks and record this figure (rear reading).

5. The difference between the front and rear readings is the toe-out condition of the housing.

Example:
Front reading......62-3/16"
Rear reading.......62-1/16"
Toe-out...............2/16" or 1/8 "

6. Rotate the rear wheels so that the scribe marks are directly underneath the vehicle (on a frame contact hoist), or as near the bottom position as possible on a twin post hoist or jack stands. Again, measure the distance between the scribe marks and record this figure (bottom reading).

7. The difference between the bottom reading, obtained in step 6, and the
average of the front and rear readings, obtained in steps 3 and 4, is the camber condition of the housing.

Example:
Average of front and rear readings......... 62-2/16"
Bottom reading......................................62-2/16 "
Difference............................................. 0 " Camber
If the bottom reading is greater than the average of the front and rear readings, the camber is negative (-). If the bottom reading is smaller, the camber is positive (+).

8. If the results of the measurements taken do not fall within the following specifications, it will then be necessary to change the rear axle housing.
Tape measure specification:
Camber.....0 ± 5/32"
Toe-Out.....0 to 3/16"

9. Refer to Ford Shop Manual for proper technique for rear axle housing replacement.

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