1956 Fastwin 15 Drive Shaft and Impeller Issues

[Matt_Stalls]

Hi all, my first post on this forum,
I have been in the process of repairing a 1956 fastwin 15 for a while now. I had it functioning for a short period of time, but it's back on the bench.

What's wrong:
-No coolant water is being pumped
-Stiff Shifter
-Likes to pop out of gear

Today I wanted to open up the lower to replace the impeller, since I figured maybe I got a crappy one that wore out super quick, but, once I opened it up I saw the impeller looks fine. The issue looks like the impeller key had worn down by grinding on the wear plate and could no longer drive the impeller.

Does anyone know why this would happen? The drive shaft have some vertical play and it almost seems like it is sitting lower than it should be, causing the impeller key to be in contact with the wear plate. Maybe my three issues are related?

Seeking guidance, thank you!

 

[Matt_Stalls]

I have attached a video of the shaft play, and of the worn key
View attachment Shaft_Play.mov

 

[racerone]

Pull lower unit apart.----Some pinion gears use a circlip to position the driveshaft.----Clip might be missing / broken or rusted away.

 

[OptsyEagle]

I will add the disclaimer here that I have never worked on a 1956 15Hp motor, but I have a 1961 5.5Hp and going from memory I don't remember that little hole in drive shaft down by the impeller. On my 5.5Hp the driveshaft has a little hole like that but it is up towards the powerhead. It has a little pin that goes through it and that pin holds up all the stuff used to seal the crankcase from water. I also know the drive shaft can be pulled out of the gear case quite easily on my 5.5Hp.

Is it possible someone flipped the drive shaft where the crankshaft splines are now going into the gearcase and the gearcase splines are now going into the powerhead? I don't even know if that could be even done.

Again, maybe the 56' 15Hp is of a completely different design and they use a pin in the driveshaft in the gearcase as well and if so just disregard my post.

 

[racerone]

????----On the 5.5 HP there is a hole for a pin / key to drive the impeller !------Not possible to install driveshaft upside down on a 56 model 15 HP.

 

[Crosbyman]

on the 5.5 and similar size engines you have a split pin holding all the " stuff" upwards against the PH .. carbon seal spring base etc...
no such things on a 15hp so no such PIN top side of the shaft ..just splines to grease.

 

[racerone]

The pin at the top of the driveshaft rotates / drives the seal assembly.