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4JH with KM4A-2 gear clunks when engaged

nesdon

New member
The transmission in my co-op club's Oldport 26 launch clunks lightly when shifting into either forward or reverse. I volunteer to lead the maintenance and repair of the launch. I'm pretty sure it has a 4JH with a KM4A-2 trans.

We had the transmission overhauled last year by East Coast Marine Transmissions, an old and well respected shop. The launch has been really heavily used and the trans was a few decades old and was badly worn out, requiring lots of new parts.

It works great, but one of the launch captains has complained about about the clunk, as it was not happening before the rebuild. East Coast says not to worry, and that this is normal, but I have been asked to pull the trans again and return it to them. I doubt they will be able to see anything with it out of the boat, and would sooner spend my time on more important tasks.

Is a small clunk when engaging this sort of cone clutch normal? My hypothesis is that the old parts, being looser, may have reduced the loading in neutral and so minimised the clunk.
 
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