4 Speed Automatic

Clean pump and support components with solvent and dry them with compressed air.

Check condition of the seal rings and thrust washer on the reaction shaft support. The seal rings do not need to be replaced unless cracked, broken, or severely worn.

Inspect the pump and support components. Replace the pump or support if the seal ring grooves or machined surfaces are worn, scored, pitted, or damaged. Replace the pump gears if pitted, worn chipped, or damaged.

Check the pump vent. The vent must be secure. Replace the pump body if the vent is cracked, broken, or loose.

Inspect the pump bushing. Then check the reaction shaft support bushing. Replace either bushing only if heavily worn, scored or damaged. It is not necessary to replace the bushings unless they are actually damaged.
Install the gears in the pump body and measure pump component clearances as follows:
a. Clearance between outer gear and reaction shaft housing should be 0.010 to 0.063 mm (0.0004 to 0.0025 inch). Clearance between inner gear and reaction shaft housing should be 0.025 to 0.177 mm (0.001 to 0.007 inch). Both clearances can be measured at the same time by:
1. Installing the pump gears in the pump housing.
2. Position an appropriate piece of Plastigage across both gears.
3. Align the plastigage to a flat area on the reaction shaft housing.
4. Install the reaction shaft to the pump housing.





5. Separate the reaction shaft housing from the pump housing and measure the Plastigage following the instructions supplied with it.
b. Clearance between inner gear tooth and outer gear should be 0.08 to 0.19 mm (0.0035 to 0.0076 inch). Measure clearance with an appropriate feeler gauge.
c. Clearance between outer gear and pump housing should also be 0.010 to 0.19 mm (0.0035 to 0.0075 inch). Measure clearance with an appropriate feeler gauge.