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Trying to identify an inboard transmission

S

Spineguy

New member
I have a 1939 Chris Craft replica that has a 4.3 Mercruiser but I do not know what transmission it is mated with. It started making a light clacking sound at low RPMs earlier this summer and now sounds like a marching band. The builder had the boat stored for 20+ years and in his late 80’s now does not remember any details of the boat. I cannot see any identifying tags or numbers on the transmission. Any suggestions?
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The gear's case appears to be a velvet drive without any reduction unit (its a 1:1 unit).

Based on the cooler return hose location, I'd say its a 70 or 71 series with a B or C version. it should have an ID plate riveted to the case.

Based on your description, the gear may be fine but the damper plate's springs may have failed. many times, removing the inspection port cover on the flywheel housing will let you inspection the plate...and yes, you will need a good flashlight.
 
makomark said:
The gear's case appears to be a velvet drive without any reduction unit (its a 1:1 unit).

Based on the cooler return hose location, I'd say its a 70 or 71 series with a B or C version. it should have an ID plate riveted to the case.

Based on your description, the gear may be fine but the damper plate's springs may have failed. many times, removing the inspection port cover on the flywheel housing will let you inspection the plate...and yes, you will need a good flashlight.
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Thank you very much for your feedback. I will be pulling the engine and transmission out next week for a winter refresh.
 
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