Ford Aerostar 1986-1997 Repair Guide

Extension Housing Seal



See Figure 1

This procedure can be completed with the transmission assembly bolted to the engine.

  1. Disconnect the negative battery cable.
  3. With the emergency brake fully engaged, place the vehicle in NEUTRAL with blocks behind the rear wheels to prevent any vehicle movement.
  5. Raise the vehicle and safely support it on jackstands.
  7. Scribe an alignment mark on the driveshaft and rear axle flange to index the driveline position for installation and balance purposes. Place a drip pan below the transmission where the driveshaft attaches to the transmission to catch any fluid which may spill out.
  9. Remove the U-bolts and nuts from the rear axle flange, then remove the driveshaft. Cap the transmission extension housing to prevent lubricant leakage.
  11. Remove the extension housing seal using seal remover T74P-77248-R or equivalent.
  13. Loosen and remove the extension housing retainer bolts using a suitable socket or open-ended wrench.
  15. Inspect the counterbore of the extension housing for burrs and remove if needed using an oilstone or equivalent.

Click image to see an enlarged view

Fig. Fig. 1: Extension housing seal removal and installation

To install:

The lube hole in the replacement seal must line up with the lube hole in the extension housing.

  1. Install the replacement seal using bushing replacer T77L-7697-F or equivalent. Make sure that the lube holes align correctly. Install the seal until it bottoms out in the extension housing.
  3. Remove the cap from the extension housing, then install the driveshaft, making sure the marks scribed on the driveshaft and rear axle flange are in alignment. Install the U-bolts and nuts and tighten the nuts to 8-15 ft. lbs. (11-20 Nm).
  5. Lower the vehicle and connect the negative battery cable. Check the fluid level and add fluid if needed.