Replacing gear select rod in Mariner 5hp 2-stroke

[wilmot14]

Gentlemen (and all ladies who check this forum),

As the title indicates, a problem has arisen in the (until now) relatively smooth process of checking the impeller and water pump on my outboard motor.

The engine is an elderly (circa 1993?) Mariner 5hp 2-stroke: serial number no longer legible. After reassembling the water pump, refitting and securing the leg, and tightening the pinch clamp to the gear select rod through the hole in the side of the leg, I found that the gear select lever would not move from reverse. It was set to reverse to gain access to the clamp through the hole to the pinch clamp. (With the pinch clamp loosened, the gear select lever moves as normal, so the problem lies in the gearbox, I assume). Having loosened the pinch clamp and dropped the leg, I found there was a small amount of vertical movement in the rod (about a couple of centimetres). But when I removed the cover and plastic guide-cum-grommet that fits around the rod and holds it in place as it enters the gearbox, I found that the rod was detached and could be lifted out.

Nothing appears to be broken; the stepped ends of the rod (which presumably move gears to select forward, neutral and reverse) is unblemished. But what has it become detached from? And how can it be replaced?

YouTube offers videos featuring a number of helpful outboard owners doing various bits of maintenance, but I have not yet found one tackling this particular problem.

So, the maroon is being sent up on this Forum. All guidance will be gratefully received – providing I master launching this thread.

 

[VicS]

I dont think anything is detached. The lower shift rod and "cam" will lift out

The "cam" on the bottom of the shift rod pushes against a plunger or " cam follower" in the end of the prop shaft. That in turn moves the clutch along the shaft to engage with the gears. Reverse is engaged when the cam depresses the follower. It is returned to neutral and forward by the pressure of a spring.

I would have expected reassembly to have been merely a question of clamping the upper and lower shift rod back together in the same positions relative to each other. I take it you forgot to mark the position of the clamp.

I'd think perhaps that the lower part has moved from the reverse position.

Push the lower rod down and verify that reverse gear is engaged. Then refit the clamp with the selector lever also in the reverse position


Diagrams at http://www.boats.net/parts/search/M...613 THRU 0T894438/Shift Components/parts.html
and http://www.boats.net/parts/search/M...U 0T894438/Gear Housing Components/parts.html

Although of later models should be pretty similar to yours

My only fear is that having removed the lower shift rod the cam follower may now be making it difficult to refit it correctly

 

[wilmot14]

Thanks so much for your swift reply and words of sense, all of which I understand. I think you may be right about the cam follower being the problem in making it difficult to refit the lower shift rod. (I am sure you are right too in my failure to connect the two parts of the shift rod correctly.) I will investigate tomorrow, but if the cam follower (under pressure from its spring) is the problem, what would be the best way to ease that, so that the cam at the end of the rod can be refitted?

 

[VicS]

Thanks so much for your swift reply and words of sense, all of which I understand. I think you may be right about the cam follower being the problem in making it difficult to refit the lower shift rod. (I am sure you are right too in my failure to connect the two parts of the shift rod correctly.) I will investigate tomorrow, but if the cam follower (under pressure from its spring) is the problem, what would be the best way to ease that, so that the cam at the end of the rod can be refitted?

I dont think the spring will push the cam follower any further than its normal forward gear position so if it has come out a little too far it should be able to ease it back with a long screwdriver blade. Then it should be possible to refit the lower shift rod assembly ....

I hope.

 

[wilmot14]

Bingo! You are absolutely right. I followed your advice, refitted the selector rod, topped up the gearbox oil etc and the engine is now running and switching gear as it should. Very many thanks.

 

[VicS]

Bingo! You are absolutely right. I followed your advice, refitted the selector rod, topped up the gearbox oil etc and the engine is now running and switching gear as it should. Very many thanks.

Good.

Thanks for the feed back.