1956 Fastwin Driveshaft won't align...what am I doing wrong?

[LokiPoki]

I have a 1956 Evinrude Fastwin 15hp that I pulled the lower unit from to replace the impeller and plate. Upon trying to replace the lower unit, I am unable to get the drive shaft to align in the motor so I can get it back together. The shifting linkage is aligning fine and the water tube is also going into place but the drive shaft will not align for me. I have spun the prop to try to get the teeth to align while pushing the lower unit up but no luck. I have done lower units on my 5.5 and 10 hp Johnson twins 58's so I am pretty familiar with these old motors, however this one acts as though I am missing something. Anything I may be overlooking? Is there a trick to these?

Thanks

 

[HighTrim]

No tricks. Same methods would apply like the others you have done.

Was the old o ring still in the groove on below the splines? Perhaps it had rotted and is still up in the bottom of the crank?

Only put grease on the splines, NOT on the top of the driveshaft.

I shift the motor into FWD gear, that gets the upper shift rod up and out of the way for now.

Ensure you put new grease on the splines, the water tube, and around the inside edge of the water tube grommet on the impeller housing. This ensures it slides in smoothly, and does not bind, causing water restriction.

Shift the gearcase into Reverse.

Slide the gearcase up, align the water tube into grommet, and slide up. If it stops before the halves mate, rotate prop CCW (youre in reverse), while pushing up. It should slide up that last half inch when the splines engage. Put a bolt in to hold it. Then, through the access panel, pull the lower shift rod up into Neutral, and shift the upper shift rod down into Neutral. Ensure the detent is lined up perfectly in the hole, then install the bolt. Test all the gears. If you are happy, install the remaining bolts and you are done.

Other thoughts:

Your 1956 15hp had a trouble spot. The lower crank seal is a weak spot. If it has not been changed, it is likely shot. They get so bad that they fall apart. This allows water into the powerhead. Obviously bad. It may have fallen apart, and a chunk of it keeping the drive shaft from engaging? Seems unlikely that it could get up in there, but who knows. Regardless, while you are it this, I would change the seal if you have not already.

 

[LokiPoki]

The edge of the upper water tube grommet is damaged but the interior surface still looks to be in good shape. The O ring on top in the groove on the drive shaft was intact and in good condition, but I replaced it anyway just for good measure. I will research the lower crank seal and figure out where to get one and replace it as well. I have never had a shaft not just pop right in before, this one has me puzzled and a little frustrated. I just started with this motor so I want to go through it good and make sure everything is serviceable. If I do have to change the upper grommet for the water tube...how big of a job is that? Thanks for the info, I appreciate your help. I will keep marching forward and see if it will cooperate today.

John

 

[HighTrim]

How much of a gap is there?

The seals originals PN is 303804. Ill send you a PM on a better replacement.

I like to have a new 303892 base gasket on hand as well when I do them as they are often torn up removing the powerhead.

The upper grommet is not too bad to do. I believe, but not sure, that there is a hole in the side of your leg where the grommet is. That hole allows you to insert a punch, which depresses the tab in the grommet, allowing you to pull it out from below. The tabs lock it in as you know.

Then to reinstall. Grease well. I made a stepped tool which holds the grommet and allows me to push it up into its spot. As you push up, again, push the punch in the hole, to depress the tab, allowing the grommet to slide into its spot. Sort of need 3 hands. After you do a few it gets easier.

 

[F_R]

It probably has the stainless steel baffle plate under the powerhead. You have to "feel" around to get the drive shaft entered through the baffle, before it gets to the crankshaft splines. Sort of like sticking it into the bottom end of a funnel.

All this is moot if you are going to pull the powerhead anyway. It's easy to install the lower unit first, then the powerhead.

 

[LokiPoki]

I am excited about this motor. I had it running in minutes after trying to start it...but wasn't pumping water so I shut it down quickly. I am definitely going to install the lower unit first and then once I replace the gasket and crank seal it should go back together much easier. I will be soda blasting the entire motor and paint and decals will all be replaced. Thanks to you guys for your help and advice and suggestions...greatly appreciated!!