Shift detent on McCullouch 9 low profile?

[billw]

No pictures yet. I’m currently flogging above said motor. When the lower unit is off, if you look under where the water pump lives, there is the shift shaft stub. It can be moved in a twisting motion, right and left, with a large, straight-blade screw driver. There is a definite feel of a neutral detent, but no feel of any detent for forward or reverse. I don’t see any other place in the shift system where the shift would stay put in forward or reverse. It shifts but it just doesn’t seem right to me. Any thoughts?

Long live American manufacturing!

[Tom]

I don’t know how far the previous owner might have gotten into that motor…  IIRC, there is a tiny ball at the end of the propshaft that’s involved with the detents.  Very easy to miss it if the lower unit is apart.  I think you should find a parts diagram with this one, Bill.

Tom

[wedgie]

Maybe you find this helpful.

https://web.archive.org/web/20120128201730/http://www.agott.com/glassboat/manuals.html

• This reply was modified 1 year, 2 months ago by wedgie.

[billw]

Thanks for both those posts. I do have a genuine, paper McCullough parts book, and even a rudimentary ABOS service manual, that covers my exact gear case. It did show a detent ball and spring but it wasn’t clear to me how it worked, until I took it apart yesterday, at lunch. It does have a three-position detent setup. When I hold the shift cradle and bearing housing in my hands, it will definitively snap into forward, neutral and reverse. When I assemble it into the gear housing, I loose the feel of forward and reverse, when I use the proper shift shaft. If I pull the shift shaft out and shift the unit with a long, wide-blade screw driver, I can feel all three detents. Everything APPEARS, to my eye, to be in good condition and not bent, worn, etc. The mystery continues.

Like my Mercury automatics, this is definitely a “think-outside-the-box” kind of motor, which makes it interesting to me. There is one aggravating thing about it, though. The drive shaft drives the pinion gear with a very small, square key. The two water pumps are mounted on a thin plate, one above, and one below the plate. This plate is sandwiched between the gear housing and the drive shaft housing. When you drop the lower unit, the plate with the pumps tends to want to stay with the drive shaft housing, rather than the gear case. That means the drive shaft pulls out of the gear housing, and the little key drops into the gear case. You have to pull the case apart and find the key, then reassemble it, which is not entirely, intuitively obvious how to do. The manual doesn’t mention this tid bit. So then, after reassembling it, you put the gear case aside, forget the trauma, then go back later, pick the case up by the drive shaft and it pull right out again, so you have to take it apart all over again!

Long live American manufacturing!

[billw]

I figured out the shift problem, or at least, a work around. If you look at picture 3, above, you see the little shift swing arm, with a slot. The slot is where the shift shaft comes down and engages. So, when the shaft twists back and forth, the arm swings, which moves the sliding cradle fore and aft. I could see, from shifting it with a screw driver, that the cradle would move full travel if the shift arm was just a little bit longer. Well, THAT would never happen, so I relived a 1/16 of an inch from one side of the shift shaft. Now, when it shifts, the arm slides that extra 1/16 sideways on the shaft, allowing a tiny bit more linear movement of the cradle, and it hits the detent in both directions. Again, there is little to no wear in this unit. I cannot imagine why I had to make this mod, unless the design was wrong from the start. Anyway, I am pleased and just thought I’d share. Obviously, these are not popular motors in the club. Picture one is the shaft as it came from the factory. Picture two is after I relieved one side of the engagement area.

Long live American manufacturing!

[Author]

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