YANMAR CONE- CLUTCH TRANSMISSION

Status
Not open for further replies.
S

Scott Wagner

I recently bought a 1985 31' boat. The surveyor didn't catch the problem with the transmission bucking and banging ( it sounds like the engine and trans are breaking their way through the bottom at low rpm -- not higher than 1950 rpm.) I am told that the cone-clutch in the trans needs to be replaced. has anyone had experience taking the trans out of the boat? how difficult is it; what to watch out for, etc.?
 
G

Garrett Pensell

folding prop?

Do you have a folding prop? We have had a couple of boats with worn-out props, and one with a brand new folding prop that had trouble opening at low engine RPMs. In the case of the brand new prop, the manufacturer blamed the clutches in the transmission. He claimed "we have problems all the time with clutches slipping on the Yanmar GM." I respectfully disagreed with him. We work on literally hundreds of GM series Yanmars, and VERY rarely have transmission issues. In your situation and in the other I describe, I do not deny that the transmission could well be the problem. However, I think there are a number of other more likely and less costly issues to check out first: folding prop not opening, misalignment of engine, helm controls not moving trans. control horn all the way into gear, bent prop, bent shaft, worn cutless, crab pot line wrapped up, etc. Hope this helps...
 
S

Sam Lust

Yes, I have

2GM yanmar. Same symptoms. The gear is easy to get off. Unbolt the flange and push the shaft aft. Remove 8 bolts and pull gear aft and out. I had Mack Boring rebuild mine to the tune of $4oo. New cone, bearings and seals. I time hadn't been a factor I would have done it myself. If you have any doubts, let the pros do it. I'm sure you can get yours to Torreson easily enough. Make sure you use straight 30 weight in the gear, not the 15w40 recommended for the engine.
 
Status
Not open for further replies.