FORDification.com TSB Database

TSB #127 - November 21, 1969
(F-100/350, P-350/400, P-3500/4000 and E-300 - 1965-1970)

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If rear axle housing misalignment is suspected, perform the checking procedure outlined below.

This article describes the procedure for checking rear axle alignment to determine if a complaint of abnormal rear tire wear is actually the result of a "bent" rear axle housing.

1. Raise both rear tires off of the ground.
2. Using chalk or a suitable marking medium, mark a strip approximately 1/2 to 1 inch wide in the center of each rear tire tread, turning each wheel to get an even distribution around the tire circumference.
3. Using a trammel bar or equivalent, scribe a mark in the chalked (marked) section of each rear tire by slowly rotating the wheel/tire while scribing the mark.
4. Place a chalk mark on the outside side wall of both rear wheels to be used as a "reference mark".
5. With both "reference marks" pointing to front of vehicle, measure the distance between the scribe marks (center of each rear tire) of both rear wheels at the "reference mark" area. Record this measurement which is the "front of tire" reading.
6. Rotate the rear wheels so that the "reference mark" of each rear wheel now points to the "rear of vehicle". Measure the distance between the scribe marks on the center of each wheel at the "reference mark" area. Record this measurement which is the "rear-of-tire" measurement.
7. Subtract the above "rear-of-tire" measurement from the "front-of-tire" measurement to obtain the "toe-out" condition of the rear axle being checked. The following are the toe-out specifications for each axle assembly:


• Dana Model No. 44 - "0" Inch to 1/4 inch toe-out
  
• Dana Models No. 60-3, 60, 70 - "0" inch plus or minus 1/4" toe-out
8. Rotate both rear wheels so that the "reference marks" are pointing down. Measure the distance between the two rear tire scribe marks. Record this measurement as "bottom-of-tire" reading.
9. Average the "front-of-tire" reading and the "rear-of-tire" reading, and using this average figure, note, that if the "bottom-of-tire" reading is greater than this average figure, the camber reading is negative (-); if the "bottom-of-tire" reading is smaller, then the camber is positive (+). The following are the camber specifications for each axle model:
camber specifications for axle model:


• Dana Model 44 - "0" Inch to 3/16 Inch - Positive Camber
• Dana Models No. 60-3, 60, 70 - "0" Inch to plus or minus 3/16 Inch - Camber
10. If the axle housing being checked does not meet the above "toe" and/or "camber" specifications, then the axle housing should be replaced as outlined in Group 4 of the 1968 Shop Manual.

NOTE: Under no condition, should a verified "bent" rear axle housing be straightened. in addition, axle housing replacements should be made under the warranty only in those cases where the out-of-alignment condition is a result of a manufacturing defect. Bent rear axles due to overload or vehicle abuse are owner responsibility.

WARRANTY STATUS: INFORMATION ONLY