Gearbox/Drive

Regardless of your choice of engine it is almost certain that the supplied gearbox will be a PRM Newage product the most popular units being the PRM 150 on smaller engines and PRM 160 on larger engines. Their market domination says it all for the quality and reliability of their products.

PRM marine transmissions have established a world-wide reputation for quality, reliability and in-service performance, making them the ideal choice for pleasure, workboat and fishing vessel applications.

All PRM hydraulically operated gearboxes feature a twin countershaft design, which enables full rated power to be transmitted in ahead or astern, with either left or right hand propellers.

PRM80 and 120 are mechanically actuated with adjustment-free cone clutches.

When correctly matched to engine and propeller, every PRM unit will provide trouble-free operation for many years.

All parts are designed for maximum reliability over an extended service life

In addition, running gear components are carefully specified and machined to the highest quality standards to ensure quiet and smooth operation.

PRM 150

FULL HYDRAULIC OPERATION
LIGHTWEIGHT, COMPACT & RUGGED
The PRM150 marine gearbox is purpose built for use with both pleasure craft and commercial boats; its twin countershaft design provides separate oil-operated multi-disc clutches (which need no adjustment) for ahead or astern drive allowing full rated power to be transmitted continuously in either direction.

The reduction ratios offered (1.53:1. 2.09:1 and 2.82:1) are all available for left-hand or right-hand propeller rotation in "ahead", making PRM150 particularly well suited to twin engine installations.

The heavy duty aluminium alloy gearcase is internally ribbed for rigidity and strength and consists of two separate halves to facilitate servicing.

The hydraulic operating system functions on normal multigrade engine oil, avoiding the need to use automatic transmission fluid, and ensures rapid response to movements of the operating lever for good boat handling. The operating lever has a positive neutral detent and is suitable for use with proprietary single lever remote control operating systems.

Robust and reliable, the hydraulic system is nevertheless provided with a mechanical lock up device for added security, so that in the unlikely event of a hydraulic failure the boat can be brought safely back to port. Access to this device is via the detachable manifold on the rear of the gearcase which also houses the hydraulic control valve.

PRM 260

FULL HYDRAULIC OPERATION

The PRM260 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 continuously in either direction.

The PRM260 is offered in two different configurations; in-line and with offset output shaft.

A choice of 1.96:1 and 2.94:1 reduction ratios is available; each will provide left-hand or right-hand propeller rotation in "ahead", making the PRM260 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.

The PRM260C input shaft, spline, adaptor flange and mounting pads are as used on Borg Warner (Velvet Drive) and Paragon gearboxes.

The hydraulic operating system functions on normal lubricating oil of the same viscosity as that used in the engine, avoiding the need to use automatic transmission fluid, and ensures rapid response to movements of the operating lever for good boat handling. The operating lever has a positive neutral detent and is suitable for use with proprietary single lever remote control operating systems.

Robust and reliable, the hydraulic system is nevertheless provided with a mechanical lock-up device for added security, so that in the unlikely event of hydraulic failure the boat can be brought safely back to port. Access to this device is via a detachable cover located on top of the main gearcase.

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 maximum engine speed of up to 1200 rpm.

Hydraulic Drive Systems

We regularly build boats utilising hydraulic drive systems but it is our view that these systems are fitted as a solution to a problem on boats where the design dictates that the engine needs to be located in a unconventional location.
This being the case on boats with central wheelhouses and rear cabins where the engine is forced to be located beneath the wheelhouse floor.

Although the sails pitch from the manufacturers suggests otherwise we do not feel that installing these systems were the design does not dictate is beneficial. The hydraulic system is less efficient than a conventional drive and takes up a greater space, plus costs of the larger engine to offset the lost efficiency and the cost of the drive system alone make the system very unattractive.