How to judge gearbox condition?

[nofacey]

Hello. I have a ZF250MA, installed new 4yrs ago, now has 1700hrs. Shifts & drives well, has own oil cooler, runs just barely warm to touch. When I’ve changed it’s oil, always clear and had no burnt smell. My concern is that I’ve done 1/2 a circumnavigation, with my feathering prop frequently not feathered(different story)......so let’s say 10,000nm of rotating undriven.

I’m going to haul soon, and pull the motor for maintenance.....and I’m wondering how to judge the condition of the gearbox without sending it away.

Any simple, proven techniques from someone that knows transmissions?

Norm Facey
SV DreamCatcher
Presently Port Elizabeth, South Africa

[SailsWithFists]

Just like an engine, an oil sample test can give some indication (provided it is used oil.)