Hello Gerhard,

This question comes up occasionally.

ZF Marine may imply that it is acceptable to use their mechanical transmissions to drive a left hand propeller.

We recommend against doing this.

The ZF mechanical transmissions use a very small intermediate gear in the transmission to provide a counter clock wise prop shaft rotation. This counter clock wise prop shaft rotation gives reverse thrust when used with a right hand propeller.

This small intermediate gear is fine for occasional use in reverse but is not adequate for full time use to drive a left hand propeller for forward thrust.

Adding an oil cooler will not make the difference.