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  • Planetary failure
  • Planetary wear


Insufficient lube oil and/or excessive clearances.


This kit offers replacement parts for rebuilding damaged rear planet assemblies and gives rebuilders the option of replacing only the worn components.

4L65-E, 4L70-E

Planetary Rebuild Kit
Part No. 77732-RK

5 Pinion Rear Planetary

View Instructions

The rear planetary assembly in GM 4L65-E transmissions frequently wears out and must be replaced. Planetary assembly wear is generally caused by insufficient lube oil and/or excessive clearances. Lack of lube causes excessive heat in the pinion gear area and causes the roller bearings to gall the gear bores and pinion pins. If there is excessive thrust washer wear or endplay, the roller bearings can run without fully contacting the gear bore, causing premature failure of the assembly. Sonnax rear planetary rebuild kit 77732-RK contains the replacement parts necessary for rebuilding damaged five-pinion planets.

  • Helical pinion gears made of case-hardened alloy steel
  • Needle rollers are closely toleranced to be used specifically with matching pins and gears
  • Kit can be combined with 77731-09 planetary bearing for a complete planetary rebuild

Can be used to service four-pinion planets with solid pins.

  • Helical Pinion Gears (5)
  • Solid Pinion Pins (5)
  • Needle Rollers (100)
  • Pinion Thrust Washers (10) Round
  • Tri-metal Thrust Washers (10)
  • 77732 rk combo
  • 77732 rk