PRM 750D Drop Centre Marine Gearbox (Ahead Ratio 2.9:1) PRM-750D3
PRM
Recommended Retail Price
£5,170.19 Inc. VAT
Online Price (inc. VAT)
£4,588.55
Sorry, this item is out of stock - Please contact us if you would like to order this on back order as our inventory is changing all the time and we might be able to get this in for you at short notice
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Full hydraulic operation: offset or down angle output shaft.
The PRM750D and PRM750A marine gearboxes are purpose built for use in both pleasure craft and commercial boats; the 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.
To cater for the widest possible variety of boats the PRM750 is offered in two different configurations : with offset output shaft (PRM750D) and 8° down angle output shaft (PRM750A). 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 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 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 response to movements of the operating lever.
The operating lever 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 the boat can be brought safely back to port.
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 PRM750D & PRM750A 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.
An electronically operated trolling valve can be fitted, which will allow variable speed of the propeller to zero whilst allowing a maximum engine speed of up to 1200 rpm.
It is essential for the engine, transmission model, reduction ratio and propeller size to be correctly matched so that the engine can attain its rated speed appropriate to the relevant service classification without labouring.
It is also necessary to ensure the torsional compatibility of the complete propulsion system from engine through to propeller, since disregarding this may result in gear noise, particularly at low speed operation, and may even result in damage to the engine as well as the transmission components.
Working Oil Pressure
Minimum - 30.34 bar (440 PSI), Maximum - 33.44 bar (485 PSI). Two tapped holes 1/8" BSP on the top, and M18 x 1.5 on the side of the valve block are provided so that the pressure gauge can be fitted if required.
Oil Cooling
The normal operating temperature of the oil should be in the 50°C - 80°C range and should not be permitted to exceed 90°C. An oil cooler is necessary to ensure that correct operating temperatures are maintained, and two 3/8" BSP connections are provided on the valve block to allow it to be fitted. The size of the cooler required depends on a number of factors including the transmitted horsepower, operating speed, duty cycle, inlet water temperature and ambient temperature.
Propeller Thrust
Both ahead and astern thrust is carried by the output shaft bearings which are of adequate capacity for all factory approved ratings.
PRM750 Gearbox spline: 17 teeth 16/32 DP. PRM 750 Gearbox coupling: 6", 6 holes, 4¾" PCD, 3" female register. Oil Capacity: 2.5 litres (4.4 pints).
| Gearbox Manufacturer | PRM |
| Construction | High Grade Cast Iron Gearcase |
| Ratio Ahead Stern | 2.904:1 |
| Nominal Power Rating Pleasure | 8.00 BHP / 100 RPM |
| Nominal Power Rating Light Commercial | 7.50 BHP / 100 RPM |
| Nominal Power Rating Heavy Commercial | 7.02 BHP / 100 RPM |
| Gearbox Spline | 17 teeth 16/32 DP |
| Gearbox Coupling | 6", 6 holes, 4-3/4" PCD, 3" female register |
| Capacity | Oil Capacity: 2.5 litres (4.40 pints) (plus the amount required to fill the cooling circuit) |
| Gearbox Model | PRM 750D |
| Approximate Dry Weight | 72kg (159 lbs) (excluding adaptor, drive coupling and oil cooler) |
| Warranty [Years] | 2 |
| Shaft Arrangement | Drop Centre |
| Hydraulic or Mechanical | Hydraulic |
| Country of Origin | United Kingdom |
| Brand | PRM |
| Replaces | PRM 401M, 402D |
Showroom & Postal Address:
Chas Newens Marine Company Limited
Ashlone Wharf Boat Yard
Embankment
Putney
London
SW15 1LB
Phone:
0208 788 4587
Delivery
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UK Standard Delivery
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International Delivery
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Delivery further information
The delivery charge is automatically added to your order and you will see the total amount you have to pay before you confirm the order. Unfortunately we have to charge carriage but we do attempt to keep it to a minimum where possible
All orders leaving us require a signature, and the delivery could take place any time between 8am and 6pm depending on the courier used. If you are liable to be out, please give an alternative delivery address or type instructions into the notes section as you place your order.
Standard Service; We will aim to dispatch goods within 3 working days. Delivery on the standard service is via courier, will require a signature and we aim to deliver within 5 working days. This service will only arrive on working days.
Courier delivery; The majority of our parcels will be sent via a courier, the bulk of which are with APC Streetwise. Please be aware that they advertise their delivery times as anywhere between 8am - 6pm Monday to Friday. We are not able to dictate to them a time slot. And in most cases a signature will be required.
New! For 2020 – Putney EmbankmentClick & Collect service; New for 2020 finds our first ever collection point on the Putney Embankment. Please select Pick Up at checkout to activate the service
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ANTIFOUL & PAINT ORDERS; Please be aware that we can only send antifoul & Paint products within GB Mainland. We CANNOT send antifoul & paint outside of GB Mainland. If you have any questions regarding this please feel free to contact our Mail order department.
LIFEJACKETS & CO2 CANNISTERS; Please be aware that we cannot currently send lifejackets with CO2 cannisters included outside of GB Mainland
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SALE OF KNIVES; In accordance with UK Law (The Offensive Weapons Act 1996), we are unable to sell knives to anyone under 18 years of age. We are unable to send knives to overseas destinations. You must upload a copy of a valid identity document to your order at time of ordering or your order will be cancelled. Knives must be sent on a signature courier service. Valid forms of ID are EU Passports, EU Photocard Driving Licence, MOD Form 90 ID Card, EU Member State National Identity Card, “PASS” ID Cards.
Last Updated 2nd September 2020
Our returns policy on items shipped within the UK is as follows:
To qualify for a refund you have 14 days from receipt of your order to notify us that you wish to cancel the order and return the goods. You then have 14 days to return the goods to us at your own expense. If you fail to notify us of your desire to cancel the order and return the goods within 14 days of receipt you are not entitled to a refund. If you do not return the goods to us within 14 days after notification you are not entitled to a refund.
Your items should be unused and in the same condition as received. They should also be in the original packaging.
To complete your return, we require a receipt or proof of purchase.
Please do not send your purchase back to the manufacturer.
If goods are faulty or damaged on receipt we will ask for photographic evidence of the fault or damage where feasible.
To read our full returns and exchanges policy, please click here.
Overseas orders may be refunded if the item is returned but we cannot refund the cost of shipping.