Re: '76 850 - Installing shift shaft into lower unit
Good news is you've done at most of the things you need to do to get the shaft back in!
There's just this one leetle, itty, bitty, teensy, weeny, little 'secret' trick to getting the lower unit more receptive to "getting the shaft".
The shift cam normally pushes against a plunger which pushes on the shift clutch to force the clutch to the Neutral and Reverse positions.
There's also a very stout spring located in the shift clutch assy that pushes the clutch firmly into Fwd gear when the shift shaft cam is in the Fwd position.
There's always a little bit of spring tension pushing on the shift clutch, so you can imagine what happens when you pull the shift shaft up out of the way, "Boing" goes the shift cam in its little cavity.
The only way to do this without disassembly is to relieve the pressure on the shift cam so it can be repositioned and the shift shaft reinserted in the cam's splines.
To do this, grab hold of the driveshaft so it won't move.
Turn the propshaft clockwise (the way it ratchets).
When you are turning the propshaft you'll feel a "click" as the "dogs" on the shift clutch "walk" up the "ramps" of the Fwd gear then fall off them.
The next time it's "just" about ready to fall off the ramp and click again, STOP. You have just relieved spring tension on the shift cam by letting the dogs on the shift clutch "walk" up the ramps and stay there. What this is doing is pushing the clutch to the rear and removing tension on the shift plunger.
So, the shift cam is now free to move about in its little cavity. Unfortunately, the cavity is not so "little" that you'll always see the cam when you look down in the hole. Not to worry, the cam cannot move far enough to be forever lost or fall somewhere, it just slides around a bit.
You may need to jostle the lower unit to and fro to get the cam moving about to where you can see it. Once you can see it, you can align the hole in the shift cam and slide the shift shaft back in place.
To be sure you've got the shift shaft fully inserted into the cam, spin the shaft around and you'll be able to feel if the cam is spinning with it.
Don't worry if, while you're moving around, the propshaft falls off the "ramp", just set it up again. And you'll probably figure this out but, even residual gear oil is thick enough to keep the cam from moving about freely. Spray a little carb cleaner or other solvent or light lubricant to wash away the residual gear oil. Then the cam will rattle around like crazy.
All that's left at that point is to install a new shift bushing. Lube up the threads and O-ring of the bushing with some waterproof grease, or spread on a thin coat of Permatex #3 aviation-type gasket dressing. This serves as a barrier against salt or mineral deposit buildup, which would make the bushing difficult to remove the next time.
That oughta do the trick, lemme know how it works out for ya..........ed
