1963 Mercury 850 Outboard Neutral Shift Problem

[hoffmanuno]

Hello, I have a 1963 Mercury 850 outboard that won't shift into Neutral. The control cables were rotted, so Im doing this all by hand for now, but I can shift the motor into reverse and forward, but not neutral. Its the Full Gear shift model. It will shift into neutral if you grab a hold of the shift rod connecting to the lower unit and pull up on it very hard while shifting by hand, otherwise it won't. The previous owner said he couldnt get it into neutral at all.

 

[Texasmark]

Re: 1963 Mercury 850 Outboard Neutral Shift Problem

To get from F to R you have to go thru N. When you shift an arm (at the powerhead end) connected to a shaft twists the shaft.

This twisting action is rod connected to a thing called a "clutch dog" down in the lower unit. It's a gear that slides back and forth on the prop shaft.

If you slide it to the front it engages teeth on the back of F gear and the prop shaft turns that way.

If you move it the other direction it initially moves out of the F gear and touches nothing (N) and continuing on engages the front of the R gear and the shaft turns the other direction..........when you turn the DRIVE shaft.

I guess what I would do is to divide and conquer. Split the lower unit off and grasp the shift shaft with a pair of vise grip pliers and slowly (without forcing) rotate it back and forth while rotating (attempting to rotate) the prop. If you have adequate control there inspect your linkage at the powerhead.

If you can't control it there, there is something wrong in the lower unit. Would start first with draining the oil out of it and inspecting the oil for contamination....may give you a clue as to what's wrong.

Come back with your answer.
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Or better yet, drain the oil first, before you tear anything apart and tell us what you find.

Mark

 

[emckelvy]

Re: 1963 Mercury 850 Outboard Neutral Shift Problem

What you're describing as a "shift rod" sounds more like the reverse lockout linkage. Your Merc's shift shaft has a rotary motion, not up-and-down like Johnrudes etc.

If the reverse lockout hook is not free to move, or the lockout mechanism is otherwise binding up, it'll be very hard if not impossible to shift out of fwd into other gears.

If the reverse latch is bound up, you can use heat and/or penetrant such as PB Blaster to help free it up. Clamp a pair of Vise Grips on the latch and work it back and forth.

I'd check the action of the lockout linkage and then pull the lower unit as suggested previously.

HTH and let us know what you find............ed