Merc won't shift regardless of position of the control handle

[suburman]

Recently acquired 1983 Mercury OB, 80 HP, S/N 6235449. Had to take apart the lower unit to reinstall the shift cam and replaced the tapered bearings and a few seals and o-rings while I was in there. When I reinstalled the lower unit with the control handle in fwd and the lower shift rod in the fwd position, the splines matched up (after a few attempts) and I pulled the unit to within about 1/2" of the drive shaft housing. When I tested the shifter at the controls, the shifter cable moves and the shift rod rotates at the gear box (i can see it through the gap) but it won't shift out of forward. I clamped a pair of pliers on the shift shaft through the gap and verified that the shaft moves as the control handle moves. I seems like the shift clutch isn't getting pushed far enough forward to disengage the fwd gear or to engage the reverse gear. I couldn't find a reference in the manual to any recommended adjustments for the gear box other than some shims in a few places. Is there something else I can check or adjust. Thanks

 

[Chris1956]

That is the issue when installing the gearcase in forward. If the lower shift shaft is not turned all the way CCW, while in forward, the control often does not have enough travel to turn it to neutral.

It is best to install the gearcase in neutral. The control also must be in neutral.

 

[suburman]

Thanks for the reply. I did some more research and figured out that i had re-installed the shift cam upside down when I did all that work on it. Ironic because that cam accidentally falling off the bottom of the shaft was the reason I had to take the gear box apart in the first place. I did figure out a way to remove and replace the cam without removing the water pump, drive shaft or pinion gear. It only took about 20 minutes and the same method would probably work if you had to recover a cam that fell off inside the gearbox. Once I reversed the cam everything worked perfectly. I did install it in neutral. Thanks again for the help.