MC-1 Drive Dog failure?

Spent a bit fiddling with it. I already had it at 6"...

I eventually found a setting (backed off helm cable 6 turns instead of 4) that allowed for full engagement both directions and not using up all of my slot adjust (still using about 70% of it). Here's a video of my current results:


I can't get it to not ratchet at all after reverse and reverse not ratchet hard in gear (hand spinning). Going to have to be good enough, at least for now... it's way better than it was!

Did some checking on the other two lower cases I have.

Pulled the TN drive's impeller for laughs.. yeah, it was completly roached. Didn't take out the housing... but no wonder the guide tube was melted! Due to the case damage and stiff shifter, it's not favored for reuse.

The Gary drive needs a new prop seal... it had ran over some netting which took out said seal. From what I'm seeing this can be replaced without tearing the gear case down. The shifting feels good and unlike my current one, seems to be in the right "finger" positions (on the current drive, forward doesn't make it to straight- I think it's a bit past?). The skeg is missing a few chunks but not completely gone... might be weldable. Has a thick and ugly (brushed, not sprayed) repaint job that I don't care for but isn't a deal breaker. The big question is what condition the gears and bearings are in, considering how bad the upper case was. At some point soon I'll pull the lower case and impeller and feel. If the gears feel good, maybe just needs a new impeller and prop seal and would be a good backup case given the suspected wear issues with my current lower.

Two outings later, I have some findings:

• The drive doesn't shift right when trimmed up any significant amount. Seems my shift fork is loose and gravity is having an effect?
• My shifting went to crap like it had been during yesterday's outing... came to check it tonight and it's not locking in either direction. I'll attempt to readjust it this week... is it normal for this to happen, or is something breaking on me?

Maybe I need to swap lower units sooner rather than later?

Something is pooched. Couldn't obtain a usable adjustment (closest I came was popping hard out of gear when pushed). Per some fresh measurements:

• Helm cable has 2 15/16" travel (in spec, a lot of slop, this was measured with it pushing/pulling the lower cable to obtain the minimum travel)
• Lower cable has nearly 7/8" of play... that be the problem. Cable is slow/stiff, but it's been that way since assembly.

Given that the lower cable and upper case shift parts are all virtually new, am I safe to conclude my lower case (and it's shifting hardware) is the problem?

Might want go get a new prop seal and impeller kit for the spare lower... hard to say if it's smooth turning (some roughness, but I don't know if that's due to a lack of preload).

Thoughts on how to proceed?

ratdude747 said:

Something is pooched. Couldn't obtain a usable adjustment (closest I came was popping hard out of gear when pushed). Per some fresh measurements:

• Helm cable has 2 15/16" travel (in spec, a lot of slop, this was measured with it pushing/pulling the lower cable to obtain the minimum travel)
• Lower cable has nearly 7/8" of play... that be the problem. Cable is slow/stiff, but it's been that way since assembly.

Given that the lower cable and upper case shift parts are all virtually new, am I safe to conclude my lower case (and it's shifting hardware) is the problem?

Might want go get a new prop seal and impeller kit for the spare lower... hard to say if it's smooth turning (some roughness, but I don't know if that's due to a lack of preload).

Thoughts on how to proceed?

Click to expand...

Did some more fiddling with it. Seems the issue is a stiff lower cable. (Tried to adjust the reverse slot in reverse, and the upper cable was under a lot of compression yet the shift not slid all the way). It was stiff when first installed but it seems to have gotten worse. Shoving the cable through the housing bent the shift rod and I had to straighten it; I had to lightly use vice grips to push the cable through, the bend at the bottom was too tight?

Not yet condemning the drive since of course it won't catch reverse if the cable binds before getting there. That said, it's not enough tension to trip the shift cutoff. I got it to where FWD locks (granted, one more turn of the helm cable and it doesn't)... and RWD ratchets very hard. Hopefully good enough to get me through the rest of the season (maybe 2 outings, Labor day and end of September; the middle two weekends are booked between work and a truck show in OK)

ratdude747 said:

Did some more fiddling with it. Seems the issue is a stiff lower cable. (Tried to adjust the reverse slot in reverse, and the upper cable was under a lot of compression yet the shift not slid all the way). It was stiff when first installed but it seems to have gotten worse. Shoving the cable through the housing bent the shift rod and I had to straighten it; I had to lightly use vice grips to push the cable through, the bend at the bottom was too tight?

Not yet condemning the drive since of course it won't catch reverse if the cable binds before getting there. That said, it's not enough tension to trip the shift cutoff. I got it to where FWD locks (granted, one more turn of the helm cable and it doesn't)... and RWD ratchets very hard. Hopefully good enough to get me through the rest of the season (maybe 2 outings, Labor day and end of September; the middle two weekends are booked between work and a truck show in OK)

Click to expand...

That cable needs to have nearly zero resistance to work right before strange things happen. It has to really bind to trip the cutout on the hard. It takes much less of a bind to mess with the shifting in the water.