ZF transmission cooler overheat alarm

[marks737]

Hello. We were returning on a cruise and got an audible gear cooler over temp alarm on port eng. Gear oil temp was at around 220 deg. Shut down engine let it cool. Checked fluid level which looked ok. Dipstick not melted or deformed. Ran boat home at reduced speed with port gear temp in the 175-188 deg range. Transmission shifts smoothly, no noise, not hot to the touch. However, shaft is turning slowly in neutral. Mechanic inspected gear cooler and found partial blockage. He’s saying clutch plates are warped and need to rebuild or replace transmission. Telling me the motor must come out to remove tranny. My questions are:

1.Anyone have experience with a 390 Sundancer, Cummins qsb 5.9’s in terms of whether the motor really needs pulling or can this be done on the boat?

2. Can the boat be operated with a dragging clutch for awhile if the cooler is cleaned and temps are normal after?

3. If I need to replace or rebuild tranny, would this be covered by insurance?

Thanks!

Topic

[Tony Athens]

Start with this:

1) Exactly model of the transmission

2) 4-5 pictures of the gear showing all–top, sides and from the back looking fwd and general access of the engine / gear and room around it

3) Exact oil type and last proper service per ZF guidelines

4) Some history of past operation

5) Picture of the gauge or display that gave you this alarm

6) Dragging in neutral– Explain better. shaft is turning fwd or rev at the dock? Can you stop it with you hand?

7) If the gear cooler was partially clogged, that would mean your aftercooler would also be in bad shape as it is BEFORE the gear cooler– When was the last time it was removed from the engine, and serviced “on the bench” per my protocol? I want dates & hours

Seven items–I need a response to each if you want some decent help.

Tony

[Author]

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