Over the years the PRM marine gearbox range has been improved and the model numbers have been changed. If you have an older PRM model still in service please refer to the appropriate new model number for more information.

The table below shows the range of old PRM gearboxes that are no longer in production. The table shows when the production of the gearbox ceased and the current equivalent gearbox mode. 

Workshop Manuals

Workshop manuals are available for each gearbox as a PDF file. To download the manual, click on the model number.

PRM Model number (click for manual)	Ceased Production	Replaced By	Oil
Delta	February 1997	PRM 150D	15W40
80	September 2016	PRM 90D**	ATF Dextron II or III
120	September 2016	PRM 125D**	ATF Dextron II or III
100	August 1973	PRM 280D	15W40
101	August 1982	PRM 280D	15W40
140	December 1978	PRM 280D	15W40
160V	March 1990	PRM 280D**	15W40
160D	March 1997	PRM 280D**	15W40
260D	April 2016	PRM 280D**	15W40
175	August 1973	PRM 500D	15W40
250	March 1973	PRM 500D	15W40
265	January 1978	PRM 500D	15W40
301	April 1987	PRM 500D**	15W40
310	December 1984	PRM 500D**	15W40
302	February 1997	PRM 500D**	15W40
401M	March 1987	PRM 750D**	15W40
402D	April 1997	PRM 750D**	15W40
601S	February 1984	PRM 1000D**	15W40
601M	January 1988	PRM 1000D**	15W40
601D	February 1997	PRM 1000D**	15W40

Items marked ** are a direct replacement for the old model with the same external dimensions.

Oil

A mechanical gearbox (PRM 60, 80, 90, 120 or 125) must use automatic transmission fluid (ATF) Dextron II or III

Hydraulic gearboxes, we recommend 15W40 mineral oil (not synthetic) for typical use. For extreme temperatures see owners handbook.

Always check the oil level with the dipstick screwed down.