Extension Housing Gasket: Installation

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CAUTION: The extension housing for the 4R100 has a shoulder or a boss cast in it to hold the orifice lube plug in the back of the case. If the wrong extension housing is used, the plug may become loose and/or fall out and cause transmission damage.

Clean mating surface on transmission and extension housing. Verify that the extension has a shoulder cast in it. See Fig 1. Install NEW extension housing gasket and position extension housing on case.
Install the extension housing bolts. See Figure. Ensure parking pawl spring is properly seated in case. Connect the output shaft speed (OSS) sensor.
CAUTION: Be sure not to raise the back of the transmission too high. If it makes contact with the underbody, damage to the TSS and OSS sensors will occur.
Raise the transmission up. Install the rear transmission mount. Install the bolts and tighten to specification. See TORQUE SPECIFICATIONS . Lower the transmission on to the rear crossmember support. Install the transmission insulator and nuts.
Tighten transmission insulator nuts to specification. See TORQUE SPECIFICATIONS . Remove the transmission jack from the transmission. Install the driveshaft. See appropriate DRIVESHAFTS & UNIVERSAL JOINTS article in DRIVELINE/AXLES. Lower the vehicle.
Fill the transaxle with appropriate fluid to proper level and check for correct transaxle operation. See LUBRICATION .

Fig 1: Identifying Extension Housing Shoulder Boss (4R100)

Courtesy of FORD MOTOR CO.