Tohatsu Gearcase removal

[MJR]

I'm trying to pull the lower unit off my Tohatsu M50 D to replace the water pump. There are (2) pins, upper and lower on the shift rod joint. Is the upper pin the one to remove?
I broke a punch trying to knock that one out. The lower one is a spring pin which pushes out easily. Any suggestions on how to remove the stuborn upper one? What size should I replace it with assuming it is not reusable?

Thanks for your suggestions.
Mike

 

[TOHATSU GURU]

Re: Tohatsu Gearcase removal

Leave the other one in. You only have to remove the bottom one.

 

[MJR]

Re: Tohatsu Gearcase removal

Thanks Elvin, I was just reading some old threads and I noticed you advised that to another. I did remove the lower pin first but it was still not sliding off.
Also, if I back flush water into the tell tale tube through the lower unit it will start to pump water very nicely, however after it sits for a couple of hours it won't pump at all. Is that like "losing it's prime"? I guess I should start with the water pump seeing how the t-stat is new. Any suggestions on that?

Mike

 

[TOHATSU GURU]

Re: Tohatsu Gearcase removal

When you are adding water in reverse it is possible that a weak cooling system will seem to function, however, if that is what it takes to make it work...Then it is not working. Usually replacing the liner, plate and impeller will solve 95% of cooling problems. But, anything in the cooling system can be out of spec.

 

[MJR]

Re: Tohatsu Gearcase removal

Thanks again Elvin, I will make another attempt this weekend to pull the gearcase by removing the lower pin. The last time removed the lower pin I was unable to free the shift rod from the rod coupler, even after some WD40. Do you have any tricks that may free it? I was hesitant to get to rough with it.

Thanks,
Mike

 

[TOHATSU GURU]

Re: Tohatsu Gearcase removal

No tricks...Do you have a M50D or a M50D2?

 

[MJR]

Re: Tohatsu Gearcase removal

I have the M50D.

Mike

 

[TOHATSU GURU]

Re: Tohatsu Gearcase removal

On an older model like that it wouldn't be unusual to find that the driveshaft has become stuck into the crankshaft. You might be better off taking the engine in to a marine dealership and having them deal with it.