Boat Gearboxes

PRM Gearboxes

With over 40 years of experience, PRM Marine have built a strong reputation for the reliability, durability and performance of their range of marine gearboxes. 

At ASAP Supplies we are proud to hold one of the largest ranges of PRM gearboxes and spares in Europe, available from stock for same day dispatch. All gearboxes are covered with a 2-year warranty but when correctly matched to your engine and propeller, PRM gearboxes will provide trouble free operation for many years.

Manufactured in the UK, PRM Marine offer gearboxes from small mechanical gearboxes for small pleasure boats to large hydraulic gearboxes for work boats and fishing vessels. 

Mechanical Gearboxes

PRM offer three different mechanical gearboxes: the 60, 90 and 125 models. These are ideal for use in pleasure craft where a simple lightweight and rugged transmission is required. The gearboxes are constructed from heavy duty aluminium and are ribbed for strength and to aid cooling, eliminating the need for an extra oil cooler.

All three mechanical gearboxes utilise cone clutches for both ahead and astern which are mechanically operated and require no adjustment. 

The mechanical gearboxes will only suit engines with a standard rotation (Anti clockwise looking at the flywheel). In forward drive the output shaft rotates opposite to input shaft therefore requiring a right hand propeller. 

Hydraulic Gearboxes

For larger engines and commercial vessels, PRM hydraulic gearboxes are available which also offer a range of additional benefits and accessories. 

All PRM hydraulic gearboxes feature a twin countershaft design which enables full rated power to be transmitted in ahead or astern with either left or right handed propellers. In addition to this, with the exception of the 150, 1500 and 1750 models which like the mechanical gearboxes will only suit engines with standard rotation, the rest of the range can be converted to suit clockwise rotating engines. This conversion is done by removing the oil pump and rotating the oil pump through 180 degrees. 

Robust and reliable, the gearboxes feature a “get you home” mechanical lock for additional peace of mind. This allows you to lock the clutch in the engaged position so you can return home in the event of a loss of hydraulic pressure. 

Purposely designed for marine use, all standard version PRM gearboxes have output shafts vertically offset from the crankshaft centreline. However, to cater for the installation demands of the widest range of hulls, both the PRM260 and PRM750 are available with an in-line configuration, while down angle options are offered on the PRM750 (8°) and PRM1000 (10°), excluding 4:1 ratio versions. 

Power take off’s are available for many of the hydraulic gearboxes either as an accessory or pre-installed, such as on some of the PRM 280 models. These allow hydraulic pumps to be fitted to the gearbox to power on board equipment.

Spare parts

If you are fixing an oil leak, replacing worn clutches or reconditioning a gearbox we are able to supply the spares to service all of the current PRM gearboxes as well as some of their older models. 

We also stock accessories to install gearboxes including adaptor plates, shaft couplings, drive plates and oil coolers. 

For help in identifying the correct spares, selecting a gearbox to suit your engine or any further information on the range of PRM gearboxes, please feel free to contact us.