Gear Box
A Borg-Warner 10-18-008 2.1:1 gearbox with a reduction gear is fixed to the flywheel housing of the engine.
Technical Specification
- Type: Borg-Warner Velvet Drive (10-18-008)
- Reduction gear: 2.1:1
- Direction of rotation: Left (viewed from stern)
- Oil capacity: 1.7 litres (without oil cooler)
- Oil type:
- BP Automatic Transmission Fluid, Type A-DX
- Esso Automatic Transmission Fluid, Type A
- Shell Donax TM
- Oil pressure: about 7.5 kp/cm² – 9.6 kp/cm² (106.5 lbf/in² – 136.4 lbf/in²)
The clutch is a multiplate wet-type clutch in an oil bath, consisting of three different clutches: ahead, neutral, and reverse. The gear is engaged with a lever, which regulates the pressure for various clutches.
If the gears don’t work, check the following points:
Dipstick
The dipstick is on the port side of the gearbox. Turn it to the left to open. The dipstick has marks for upper and lower levels.
Since the oil cooler takes an additional 0.5 litres (~1 pint) of oil, the gearbox oil level should always be above the upper mark. Always use a funnel when refilling.
Gear Lever
The lever is located on the port side of the gearbox. It has a spring-loaded ball that fits in the dimples (ahead-neutral-astern) on the gear housing.
During the first 100 running hours, the control cable may stretch, and the ball may not locate into the holes when changing gears. The cable can be adjusted by turning the fork end. One possible fault may also be a loose fork end.
If you have to refill the oil, always check for possible leaks. Due to the high oil pressure, the oil jet at a leak may be very hard to see with the naked eye the unions, and check for oil stains.
The gear oil pressure is normally 7.5 kp/cm² when the clutch is warm.
The gear oil pressure gauge flickers between 7.5 and 4 kp/cm² when changing from neutral to forward. This is quite normal, since the pressure falls momentarily when the forward clutch cylinder valve is opened.
The phenomenon does not occur when changing to reverse, since the reverse cylinder is smaller.