Nissan/tohatsu 6hp shift shaft woes

[LurcherNZ]

Just replaced the water pump in my 6hp longshaft 4-stroke merc (nissan/tohatsu clone). when I came to fit the gearcase back on I ran into issues. I had it in reverse when I removed the gearcase and I tried to get the thing back together in reverse but no dice in the process I seem to have struck a problem with the shift shaft. If I turn the driveshaft clockwise then the prop shaft turns clock wise if I pull or push on the shift shaft I can't find neutral or reverse. There is a little up and down play in the shift shaft and I can rotate the shift shaft 1/2 a turn or so in either direction but I can't pick up neutral or reverse. Have I some how damaged the shift mechanism? I don't recall using any excessive force that would have broken anything?

 

[pvanv]

I take it that you still have the LU down. Seems you are in F (cam 47 rod is up). Since you can rotate the cam rod, you likely pulled the cam rod up too far -- out of contact with the push rod 23. At this point, you need to rotate the cam rod so that the flat side of the sliding cam faces aft (the offset end of the cam rod goes forward, not to the side or aft), and then get it to slide down so that it engages the push rod. You may need to release the cam rod bushing 48 to do that; If you still can't get it, you will need to release the prop shaft housing 9 to take pressure off of the push rod. If so, drain the LU lube, as it will run out past the housing o-ring once it is pulled out about 3/8". Be advised that if you remove the entire prop shaft housing, you need to be careful not to drop the push rod inside the LU.

 

[LurcherNZ]

thanks pnav I really appreciate you going to the effort to post the diagram. I took it to the local merc rep and he used a bit more force than me and snapped it back into place without dismantling anything

 

[stanirish]

I take it that you still have the LU down. Seems you are in F (cam 47 rod is up). Since you can rotate the cam rod, you likely pulled the cam rod up too far -- out of contact with the push rod 23. At this point, you need to rotate the cam rod so that the flat side of the sliding cam faces aft (the offset end of the cam rod goes forward, not to the side or aft), and then get it to slide down so that it engages the push rod. You may need to release the cam rod bushing 48 to do that; If you still can't get it, you will need to release the prop shaft housing 9 to take pressure off of the push rod. If so, drain the LU lube, as it will run out past the housing o-ring once it is pulled out about 3/8". Be advised that if you remove the entire prop shaft housing, you need to be careful not to drop the push rod inside the LU.
View attachment 201289

Pvanv, Thanks so much for these instructions. Yes, I did pull the cam rod up too far so that the cam rod was out of contact with the push rod. Before reading your post and after my first reinstallation of the LU, the outboard was in forward only. So, I had to take the LU off again and start over. I followed your directions. When reinstalling, this time I set the cam rod in reverse, that is, pushed all the way down, and set the gear lever in reverse too. And, I happened to have a small diameter length of tubing that I inserted down the LU shaft through the cam rod hole at the top and snugged it to the top of the cam rod to help guide it up and out of the hole at the top of the shaft when pushing the driveshaft and cam rod back up the housing. I had the outboard on it's side on the floor. Other positions such as upside down work too but this was the smoothest.