Ford Mid-Size Cars 1971-1985 Repair Guide

Pinion Oil Seal



See Figures 1, 2, 3 and 4

The following procedure can be used on all years and models. Slight variations may occur but the basic procedure should cover all years and models. Special tools and mechanical skill are needed for this job.

  1. Raise and support the vehicle. Remove the rear wheels and brake drums, or calipers.
  3. Mark the driveshaft and yoke for reassembly and disconnect the driveshaft from the rear yoke.
  5. With a socket on the pinion nut and an inch lb. torque wrench, rotate the drive pinion several revolutions. Check and record the torque required to turn the drive pinion.
  7. Remove the pinion nut. Use a flange holding tool to hold the flange while removing the pinion nut. Discard the pinion nut.
  9. Mark the yoke and the drive pinion shaft for reassembly reference.
  11. Remove the rear yoke with a puller.
  13. Inspect the seal surface of the yoke and replace it with a new one if the seal surface is pitted, grooved, or otherwise damaged.
  15. Remove the pinion oil seal using tools 1175-AC and T3T-100A or equivalent.To install:
  17. Before installing the new seal, coat the lip of the seal with rear axle lubricant.
  19. Install the seal, driving it into place with a seal driver.
  21. Install the yoke on the pinion shaft. Align the marks made on the pinion shaft and yoke during disassembly.
  23. Install a new pinion nut. Tighten the nut until end-play is removed from the pinion bearing. Do not overtighten.
  25. Check the torque required to turn the drive pinion. The pinion must be turned several revolutions to obtain an accurate reading.
  27. Tighten the pinion nut to obtain the torque reading observed during disassembly (Step 3) plus 5 inch lbs. Tighten the nut slightly each time, to avoid overtightening. Do not loosen and then retighten the nut. Pinion preload should be 8-14 inch lbs. (0.8-1.5 Nm).

If the desired torque is exceeded a new collapsible pinion spacer sleeve must be installed and the pinion gear preload reset.

  1. Install the driveshaft, aligning the index marks made during disassembly. Install the rear brake drums, or calipers, and wheels.

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Fig. Fig. 1: Measure the pinion bearing preload

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Fig. Fig. 2: Remove the companion flange from the rear axle assembly

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Fig. Fig. 3: Removal of the pinion seal

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Fig. Fig. 4: Pinion seal installation