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
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
310V December 1984 PRM 500D** 15W40
301M April 1987 PRM 500D** 15W40
302D 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.


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

15W40 mineral (not synthetic) for typical use. For extreme temperatures see owners handbook.

Always check the oil level with the dipstick screwed down.
Refer to workshop manual for more details.
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