Auto gearbox question.

[trike micra]

The radiator on the autos cool the gearbox as well as the engine, is it an oil cooling system or is it water?

 

[frank]

heat exchanger pipe embedded in the lower plastic header iirc

 

[trike micra]

heat exchanger pipe embedded in the lower plastic header iirc

So running a separate oil cooler similar to a motorcycle cooler might work?
looking at building another trike to my own design, a separate radiator setup is looking like the easiest way of cooling.