'78 johnson saildrive 15hp gear clack in forward

[DrFoster]

Hello there,

I've been reading this forum for about 4 months now, and haven't had to register / post until today... well, here is my first:

I have a 1978 15hp Johnson Sail drive, which is a lot like a goofy version of an outboard in the aft section of my sailboat. When I'm in reverse or neutral, all is good, no noises and good power to reverse. When I shift into forward, at any point above about 1/3 throttle, I get a clack sound about every 15 seconds. I've shifted the gear lever in and out to make sure this is the proper place for the sound, and yep, it sounds like it is re-shifting into forward.

There is no surge in power, just the normal "bzzzz" then "clack" then back to "bzzzzz" again.

I'm wondering if there is some sort of adjustment that has slipped, since it appeared so suddenly one day, or if I've broken something. I've done a lot of searching around on this topic and I can't seem to find someone who has the same problem on a saildrive and has resolved it.

I have tried to shift it into forward and hold hard on the shift lever while applying power, and it still makes the clack. I do have the service manuals, and believe it or not, the dang troubleshooting sections don't even come close to any gear problems!

Thanks for any help here.

Robert

 

[tashasdaddy]

Re: '78 johnson saildrive 15hp gear clack in forward

sound like the clutch dog in the gear case is bad. assuming it is like an outboard gearcase the teeth are very square, and when the get worn, they kick out of gear, and reengage on the next revolution. the cure is to replace the clutch dog, and forward gear.

 

[F_R]

Re: '78 johnson saildrive 15hp gear clack in forward

Exactly. It will only get worse with every "clack". Every time it clacks, it beats a bit more metal off the dog and gear.

 

[DrFoster]

Re: '78 johnson saildrive 15hp gear clack in forward

Thanks for the pointers; I'll get to work on it tomorrow and let you know what I come up with.


Robert