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  • Damaged pump gears
  • Damaged impeller hub
  • Excess pump noise
  • Low line pressure
  • Code 62, 628, 1744
  • Repeated converter failure


Wear on the pump gears and with the mating impeller hub reduces pump capacity and increases pump noise.


These direct replacement and oversized gears are specially designed to improve the fit and durability of the pump-to-torque-converter interface.

4R100, E4OD

Pump Gear Set
Part No. 36438A

Late style, OE size

View Instructions

Sonnax offers high-quality replacement gear sets for F5 and later E4OD pumps. Two designs are offered: a direct replacement gear set 36438A and an oversized gear set 36438AX-01K. Both meet or exceed OE pump gear performance.

  • Oversized gear has improved fit and durability of pump-to-torque-converter interface.
  • Direct replacement gears will work with any F5 and later pump housings with no machining required.
  • Oversized version fits F5 and later pump housings with excessive wear by allowing pump housings to be refurbished by machnining the pump cavity.
  • Both gear sets are designed to meet or exceed OEM pump gear performance.

In 1995 the E4OD pump was redesigned to utilize pump gears with 10 lobes on the outer gear. Prior to 1995 the outer pump gear had 11 lobes. The pump casting was also revised. Prior to 1995 the pump casting was designated as E9 or F1. Beginning in 1995 the casting designation was changed to F5 and is currently F8. The E9 and F1 E4OD pumps suffered from low pump output and should be replaced with an F5 or later model pump.

  • Inner Pump Gear
  • Outer Pump Gear
  • 36438a combo
  • 36438a