PRM750 Marine Gearbox

Full Hydraulic Operation:  Inline, Offset or Down Angle Output Shaft
The PRM750 marine gearbox is purpose built for use in both pleasure craft and commercial boats; its twin countershaft design provides separate oil-operated multi-disc clutches (which need no adjustment) for ahead and astern drive allowing full rated power to be transmitted in either direction.
To cater for the widest possible variety of boats, the PRM750 is offered in three different configurations: inline, with offset output shaft and with 8° down angle output shaft. Reduction ratios available are 1.09:1, 1.459:1, 1.935:1, 2.565:1, 2.904:1 and 3.952:1 (3.952:1 reduction is not available on in-line or down-angle gearboxes) all of which can provide either left-hand or right-hand propeller rotation In "ahead", making the gearbox particularly well suited to twin engine installations.
The gearcase is constructed of high grade cast iron, internally ribbed for rigidity and strength, and consists of two separate halves to facilitate servicing, the oil pump and hydraulic control valves being externally mounted for easy accessibility.
A Special Feature of the PRM750 is the direct drive power take-off which is available as an optional extra; this will power a hydraulic pump to SAE J744C type 'B' specification, thus providing an economical and space efficient means of driving on-board machinery
The robust and reliable hydraulic system uses lubricating oil of the same viscosity as that used in the engine, and helps ensure good boat handling by its rapid rapid response to movements of the operating lever.
The operating lever itself has a positive neutral detent, which assists the setting-up of the remote control operating unit whilst for added security, to guard against the unlikely event of hydraulic failure all gearboxes incorporate a mechanical lock-up device so that the boat can be brought safely back to port.
The Newage Trolling Valve is also offered as an optional extra.  This is electronically operated which allows variable speed of the propeller to zero whilst allowing a minimum engine speed of up to 1200 rpm.

 

Nominal Power Ratings,  PRM750 'A' Marine Gearbox (Angle Drive Only)
RATIOS PLEASURE LIGHT COMMERCIAL HEAVY COMMERCIAL
BHP kW BHP kW BHP kW
1.09:1,  1.459:1 9.62 7.17 7.62 5.68 7.23 5.39
1.935:1,  2.565:1 9.48 7.07 7.62 5.68 7.23 5.39
2.904:1 8.00 5.96 7.51 5.60 7.02 5.24

 

Nominal Power Ratings,  PRM750 'D&C' Marine Gearbox (In Line & Drop Centre)
RATIOS
3.95:1 in-line not available
PLEASURE LIGHT COMMERCIAL HEAVY COMMERCIAL
BHP kW BHP kW BHP kW
1.09:1,  1.459:1 10.52 7.85 8.13 6.07 7.85 5.86
1.935:1,  2.565:1 9.48 7.07 7.85 5.86 7.43 5.55
2.904:1,  3.952:1 8.00 5.96 7.50 5.60 7.02 5.24
Maximum Operating Speeds:  4500 rev/min intermittent, 4000 rev/min continuous.

Note: These powers are expressed in BHP and kW per 100 rev/min engine operating speed, and are measured at the engine flywheel.  Ratings have been established to ensure the long trouble-free life of the gearbox which should not, therefore be used at powers in excess of those shown.

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Noss Marina,  Bridge Road,  Kingswear, Dartmouth,  Devon,  TQ6 0EA
Tel / Fax: +44 (0)1803 833343,  Mobile: 07855 255217  VAT Registration No. 737 278 307