Routine Maintenance - Lehman SP90 Owner's Manual

Operation
First time usage
Before starting the engine fill the gearbox with one of the recommended lubricants (SAE30W) to the maximum level
indicated on the dipstick.
Ensure that the gearbox is in neutral, it is recommended that the optional neutral safety start switch (if fitted) should
be wired in to the starter circuit to avoid uncontrolled boat movement on starting-up. Start up and run the engine
and gearbox for a few minutes to allow the oil to circulate through the cooling circuit (and angle drive if fitted). Stop
the engine, allow to settle, check the oil level and 'top-up' to the maximum level shown on the dipstick.
Operating temperature
Normal operating temperature should be between 50°C
for fitting to Newage PRM gearboxes have adequate capacity to ensure correct operating temperature under all
conditions.
Gear shifting
Newage PRM marine gearboxes have been designed and tested to ensure rapid shifts from ahead and astern and
vice versa can be operated at full horsepower ratings and speeds, and the transmission will respond rapidly in
these circumstances. Full power shifts, however, do place abnormal, even if short lived, loads on the gearbox, and
the operating life will be increased if they are reserved for emergency use only.
Trailing (free-wheeling) the propeller.
The bearings used in Newarge PRM gearboxes have been carefully selected to ensure that prolonged trailing
(free-wheeling) of the propeller will not have any detrimental effect on the transmission. This allows the propeller
to turn freely with the engine shut down and makes Newage PRM gearboxes particularly suited for use in auxilliary
sailboats, motor sailers, or multi-engine installations where the boat may be operated with one or more engines
shut down.
Emergency operation
Included as standard in every Newage PRM marine gearboxes is a 'Get-You-Home' device, allowing the gearbox
to be mechanically locked in 'ahead' drive, in the unlikely event of hydraulic failure.

ROUTINE MAINTENANCE

After 25 hours running
Drain all oil from the gearbox and refill with one of the recommended lubricants. Operate the engine and gearbox,
allowing the oil to circulate, then stop the engine and allow the oil to settle. Re-check the oil level and top up if
necessary to the maximum mark on the dipstick.
Daily
Check oil level and make visual check for oil leaks especially at the output shaft oil seal and at gasket sealing surfaces.
Annually
Check oil cooler hoses and connections
Check propeller shaft alignment
Ensure that remote control operating linkage is adjusted to give the correct travel on the gearbox operating lever.
TWIN DISC MARINE TRANSMISSION
All moving parts of the transmission are lubricated by the oil within the sump as it travels throughout the hydraulic
system. The oil used should be of the same quality and type recommended for use in the engine. Use SAE30 HD
when the inlet water temperature to the heat exchanger is above 80"F, and SAE20 HD when this temperature is
below 85°F.
Oil level in the transmission should be checked daily with the engine at idle speed and the marine transmission in
"neutral". Oil level must be maintained at the "full" mark on the dipstick. The period between oil changes is 1000
hours of operation or 6 months, whichever occurs first. At each oil change the filter screen, installed at the bottom
of the rear cover and extending into the sump, should be removed and cleaned. It should be re-installed using pipe
sealant or pipe thread compound on the threads. The breather cap should also be removed and flushed in clean
diesel fuel. Next, disconnect the heat exchanger hoses and drain all the oil from the heat exchanger. Finally, if an
oil filter is used in the hydraulic system, drain the filter and connecting hoses, and replace the filter element.
To drain the transmission, remove the Hex-Head plug from the bottom of the main housing. When re-filling, use
1.2 US gallons (4.456 Its) of oil. Pour the oil into the breather cap opening. After filling, start the engine and shift
the unit from "forward" to ''reverse" several times to fill the oil lube lines, heat exchanger etc. with oil. Set the engine
at idle speed and the transmission in "neutral". The oil level must be to the "full" mark on the dipstick. Re-instal the
breather cap when the correct level has been reached and run the transmission until the oil temperature has been
raised to its operating range. Re-check the oil level and top up if necessary.
Periodically inspect hoses for signs of leak, damage or sponginess, replacing where necessary. Pressure and
temperature gages should be regularly inspected and replaced if found to be damaged or of suspect accuracy.
If information on any other transmission is required, please contact Lehman and such information will be forwarded
to you.
-
A26