How Hot Does Your Box Get?

[Ricky]

I have a Volvo Penta MS2A-E gearbox fitted to a Volvo Penta TMD22A engine.
My gearbox now appears to be working OK but the top gear casing is uncomfortably hot when I run the engine at 1600 rpm whilst tied to the dock. When I select reverse, the bottom gear gets uncomfortably hot. By that I mean I can touch the casing for 2 or 3 seconds before pain sets in.
I know that dockside running is putting constant acceleration power through the gearbox but I would rather have a problem here than approaching the Panama Canal!

The casing does not get hotter and the bearings are being well oiled with no signs of any wear. The oil is cooled internally by a raw water heat exchanger

I have dripped water on the casing and it does not boil or steam off so it is well below 100 deg centigrade.

How hot do you think a gearbox SHOULD get??

Thanks for your help.