Lower Unit Threads?

[OSWLD]

I recently broke my retainer in the lower unit of my '04 15 hp 2 stroke merc. in the process of removing it i messed up a few threads. Does anyone know the size/thread count that the retainer (for the prop shaft) screws in to? i know its a left hand thread too, now(reason i broke it). i need to clean thse threads out to put her back together.

 

[CharlieB]

Re: Lower Unit Threads?

You got a tough one.

Once you get your hands on the new retainer, then you can use a thread pitch gauge to check the thread.

Finding a tap is going to be a real trick. Unless you know a friendly machinist to cut you a fine thread left hand that size then cut flutes in it so you can chase the boogers out.

I bent an itty bitty screwdriver tip and slowly scratched at one until it came clean. I got lucky, I guess, but the time it took (if I was getting paid) I could have bought 2 new gearcases. (Call me stubborn) (Back then I didn't work at the machine shop that I do now)

 

[achris]

Re: Lower Unit Threads?

Why not just use one of these? It's called a 'thread file'... Just be careful... they are available in both imperial and metric...

 

[OSWLD]

Re: Lower Unit Threads?

yeah i may be able to get in there with that thread file. its worth a try! thanks.