'56 FD-10 15hp Prop Shaft Seal Replacement

[bjarnold]

I recently purchased a 1956 Johnson Sea-Horse 15hp motor that had been sitting for awile. After cleaning the points,cleaning the carburetor,changing the lower unit oil, and adding fresh gasoline the motor started right up and ran pretty good. Then I noticed grey oil under the motor. After replacing the prop shaft seal and a new O ring on the hub the motor stopped leaking oil. After spending a couple of hours trying to get this together I need some help. The motor goes into reverse but when I move the shift lever to forward the motor stays in neutral and when the shift lever is in the neutral position the the prop will spin a little then stop. I already took the plate off on the shaft and got the shift rod set right but there is still no forward gear.

 

[Paul Moir]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Did you remove the phillips screw on the side of skedge? I think the shift yolk must have decoupled from the cradle - it's the only thing I can think of that would do that.<br />If that happened, you can often get it back into place without disassembling the lower unit by removing that phillips screw and manipulating the shift lever/rod. This is much easier to do with the lower unit off the engine. You're trying to get the yolk coupled with the cradle, and the screw through the hole in the yoke.

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

I Just went out and looked and there is no phillips head screw anywhere on the lower unit<br /><br />Bill

 

[Paul Moir]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

My mistake. I was thinking of a different style lower unit.

 

[Chinewalker]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

The '56 units used a pin in a little slot in the bottom half of the gearcase bullet to act as the pivot for the shifter fork - it was replaced the the more common Phillips head screw from the outside the following year. In any case, it's not hard to misalign the pin when reassembling which would cause the unit to shift out of synch.<br />- Scott

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

I am 99.9% sure that I got the pin aligned with the slot. Is there anything else that would cause the motor to do this. I also remember the motor did this before I took the lower unit apart.<br /><br />Bill

 

[mjbrueck]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Is the lower unit bolted onto the motor, or is it off. <br /><br />If it's on the motor:<br />Check the shift rod coupler. Are both ends fully in the coupler? The coupler is brass (or bronze) so it can be tightened down on the shift rods even if they're not seated. If they're too far apart the motor won't shift all the way into forward (and neutral may be reverse).<br /><br />If it's off the motor:<br />It's probably that 0.01% of the time that the pin dropped out. Or you have a severely worn clutch dog (doubtful, based on your description).

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Today I noticed that one of the holes on the brass coupler was stripped out. So I put a new one on and found out that when the shift lever is in forward the motor is in neutral and with the lever in reverse and neutral the motor runs in reverse.

 

[petrolhead]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Disconnect the shift rod coupler, grap the lower part of the shift rod with a pair of pliers and see if you can shift it into gear manually, if it works your problem has to be with the shift rod/coupler/lever, if it doesn't the problem has to be in the gearcase.

 

[Chinewalker]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

There is some adjustment available up on the shift handle. There should be two screws at right angles to each other that you'll need to loosen and then center things up with the spring-loaded detent arm...<br />- Scott

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

The only screw I could find was below the hole for connecting a remote cable on the shift lever. I loosened it and moved the detent arm but it made no differnce. I was running the motor today and when I had the shift lever in the forward position I opened the throttle and it kicked into gear but then it went back the neutral when I backed off on the throttle. I am only guessing but I think it could be the clutch dog. Even though it not been used for a few years it has been used thru the years and it shows. <br /><br />Thanks<br /><br />Bill

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

I took the lower unit apart today and reverse'd the clutch dog and I made sure that when I put it back on the pin was aligned with the slot on the bottom housing. I fired the motor up and it still does not engage in forward gear. I am thinking it could be that the back of the forward gear is worn and the clutch dog does not engage it. ANY THING ELSE IT COULD BE???<br /><br />Thanks

 

[petrolhead]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

It has to be shift rod adjustment, the face of the gear cannot have worn to the extent that it's moved forward enough that the dog doesn't engage, for one thing you'd have a ton of metal filings in the gear oil which you could hardly fail to notice.<br />My bet is that something is wrong at the top end of the shift rod, where it attaches to the shift lever/shaft assembly.

 

[Chinewalker]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

OR, the shifter fork may be bent, OR the shift cradle may be worn. The cradles (horse-shoe shaped aluminum piece that the shift fork seats into) are prone to wear, particularly if the unit was run for any length of time without oil in it.<br />- Scott

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Chinewalker,<br /><br />When the shift cradle hooks to the clutch dog it fits really loosly and falls off. Should it be like that?<br /><br /><br />Thanks

 

[Chinewalker]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Hi Bill,<br /> It shouldn't be loose enough to slide around on its own, but it shouldn't be a tight fit, either. As long as there's no excess lateral movement to it, it should be alright. Also, check for wear on the forward and reverse faces of the cradle as that's where it'll start to lose metal if the unit was ever run without oil.<br />- Scott

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Chinewalker<br /><br />A few months ago I replaced the impeller in a neigbors 1957 Johnson 18hp and he used it for the first time since then yesterday and it will not go into forward. Is there any tricks to getting the shift rod aligned?<br /><br />Thanks

 

[Chinewalker]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Hi Bill,<br /> Did it shift fine before the impeller change? If so, then the only thing that could have gotten out of what is at the coupling. The bolts MUST align within the detent in the shift rods or it will not shift properly. There's no other adjustment to it... A penlight migh help in making sure the detent is aligned in the hole before replacing the bolt. Also, if it's a little off, the bolt is easily stripped out, so make sure it's bang on...<br />- Scott

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

Chinewalker,<br /><br />I was working on the 18hp today and I removed both bolts for the brass coupler and aligned the notches on the shift rods to the holes on the coupler and after putting the bolts back in the motor now works perfectly. So tonight I did the same thing on the 15hp and it still does not go into forward gear. <br /><br />Thanks<br /><br />Bill

 

[bjarnold]

Re: '56 FD-10 15hp Prop Shaft Seal Replacement

PROBLEM FIXED!!!!<br /><br />After removing the complete prop shaft and looking at a parts diagram it turns out that the shift craddle was missing. I located one for $4 I installed it and now the motor works great!.