Mercruiser Outdrive Parts Drawings *How to Videos

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Mercruiser Ring - Upper Gearcase Part

Upper Gear Case Part - Ring - MC-1 / MR / Alpha 1

  • GLM Marine aftermarket 28390
  • Mercury OEM part number 35983

28390 Ring - Mercruiser

28390 Ring - Mercruiser

28390 (Mercury part 35983) is installed onto the horizontal gear train in the upper gear case of the Mercruiser outdrive. To access this part, the threaded drive shaft bearing retainer - 28350 must be removed along with the lock nut 28360. To remove this part, a special tool called a bearing retainer wrench can be used for easy removal and installation. This tool is compatible with all models, including MC-1, MR, R and Alpha 1 and Gen 2 models. When working on the horizontal section of the drive housing, make sure to replace the o-ring (82380 - included in seal kit) installed behind the part along with the locknut (28360). Make sure to inspect the two bearings behind the gear for any play and replace if necessary. The seal kit, locknut and tool can be viewed below.

P/N 28390 Ring - Mercury OEM 35983 $8.00

Customers who ordered P/N 28390 also purchased:

39622 mounting gasket

39622 mounting gasket

Installation gasket P/N 39622 or OEM 27-94996A2 outdrive mounting gasket.

28350 Retainer

28350 Retainer

Retainer nut P/N 28350 or OEM 816811-1 is installed alongside #28390. Make sure to inspect threads on retainer for any damage - replace if necessary.

90100 Wrench Tool 91-17256

90100 Wrench Tool 91-17256

Retainer wrench P/N 90100 or OEM 91-17256 tool is used to remove the bearing retainer to access the ring.

87500 Seal kit

87500 Seal kit

Seal kit P/N 87500 or OEM 26-32511A1 contains all oil seals, o rings and gaskets for the upper gear housing.