ZF 25M Gearbox

[Jorge Baptista]

Hello,
i have 37" sailboat with Perkins 4108 and a ZF25M gearbox 1.88 ratio.
Is anyone here that have the same gearbox and mounted the cooling Unit?
2 months ago i replaced the clutch disks, due some wear that could be cause wrong oil usage, bad maintenance from previous owner, or by heat.
I have ordered the cooling unit for the gear box , but i don't know how to proper install the antifreeze circuit.
If anyone could have some light on this i would be very appreciated.

Best Regards.

 

[Slipstream 34]

I've fitted a cooling unit to the smaller ZF10m gearbox. The unit is cooled by sea water not the engine coolant. Fit a hose from the raw water inlet to the cooler then upto the impellor pump.

 

[Jorge Baptista]

Thanks for the reply.
So i have to fit a hose from the water restrainer to the cooler and from the cooler to the pump.
Can the pump work like that? My concern is that is a lot of pipe length until the pump.

 

[Jorge Baptista]

Slipstream 34 i manage to get a manual from ZF 25M.
The setup goes like this:
Raw water -> Water restrainer -> Water Pump -> Gearbox cooling unit -> Heat exchanger

Makes more sense this way because of the Water pump.
Thank you, i thought it was cooled with coolant. I ordered the unit but still didn't arrived so i didn't had any idea .

 

[Plum]

Slipstream 34 i manage to get a manual from ZF 25M.
The setup goes like this:
Raw water -> Water restrainer -> Water Pump -> Gearbox cooling unit -> Heat exchanger

Makes more sense this way because of the Water pump.
Thank you, i thought it was cooled with coolant. I ordered the unit but still didn't arrived so i didn't had any idea .

The gearbox oil cooler can go before or after the seawater pump, whatever gives the best hose run. On many mass produced boats it is before the waterpump.

Www.solocoastalsailing.co.uk

 

[Jorge Baptista]

Thanks for the reply Plum.
I was just questioning because the water pump should be close to the water inlet at least was what i read, i'm no nautical mechanic.

 

[Plum]

Thanks for the reply Plum.
I was just questioning because the water pump should be close to the water inlet at least was what i read, i'm no nautical mechanic.

Ideally, ALL hose runs should be short without any tight bends/elbows but in reality it's all a compromise based on, for example, the position of an existing skin fitting and a convenient position for the strainer. Same applies to the hydraulic/oil hoses from the gearbox to a remote cooler.

www.solocoastalsailing.co.uk