Taking a Long Shot

[Capt Ken]

If any have paid any attention in the inboard section, my son and myself is helping an elderly man get a hydrofoil boat up and running that he has been working on for 40 years. One of the problems we are having is the reverse lock on the old Mercruiser I drive. its a 1967 model with the bronze latch on the front of the drive that is suppose to lock the drive down like an outboard when in reverse but releases when in forward. It looks like all the parts are there by the breakdown schematic. But it will not release for the drive to raise. Its the old single hose ram that is for tilt only. I have had this thing apart a dozen times and cannot figure how its suppose to release. It appears that there is a roller on a bracket that rides on a ramp on the shift shaft. but the roller rolls but nothing is moving on the lock forks. I did find where some early models had a manual release on the side of the transom assembly but this one doesn't. BTY, this unit was bought new and has never seen the water.

 

[Bondo]

Re: Taking a Long Shot

Ayuh,.... I've never even seen 1 Ken, but I'd Guess it's gotta be in Forward to work...

It appears to be in neutral now...

 

[Don S]

Re: Taking a Long Shot

I have never seen one either, but from that picture, it looks like it's almost in forward gear (straight forward) and should push down on the lock mechanism to release if from the cross pin in the gimbal ring. Then when you go to reverse is should allow the reverse lock to move up to latch on to the cross pin. Does that shift shaft turn the same was as other one drives? Not sure why it's that far past center unless it turns clockwise from the way it is now.

 

[Capt Ken]

Re: Taking a Long Shot

The upper gear housing is sitting on the bench and not attached to the lower, that's why the shift lever it a bit too far to the left. You can see the off white plastic roller to the left of the shift shaft and it turns just like the outdrives of today. The shift shaft had two ramps and the white plastic roller rides between the ramps so it moves the roller up and down as the shaft turns. Problem is, its no way attached to the locking arm and the breakdown doesn't show anything missing. If I move the roller arm up where it touches the upper ramp on the shift arm, then it would press down when in forward. Thinking about drilling a hole on the left side of the outdrive where I can go in and drill through the two arms, thread them and connect them with a small bolt.

 

[Don S]

Re: Taking a Long Shot

If I move the roller arm up where it touches the upper ramp on the shift arm, then it would press down when in forward.

It should do that.
When in forward it should push the lock mechanism down so it doesn't hook on the cross pin in the gimbal ring. Only in reverse should the latch be up.

 

[Capt Ken]

Re: Taking a Long Shot

If I screw the two arms together like I have the screwdriver set, it should work. Maybe?
The only thing is the spring on the latch is going to want to push the shift shaft up but the shoe the anvil slides into should hold it down. I'll have to keep down pressure on the lock when reinstall the drive to keep the shift shaft from being too high to slide in the shoe.

 

[Capt Ken]

Re: Taking a Long Shot

 

[Don S]

Re: Taking a Long Shot

Push down on the shift shaft and see if the latch works. It may be that the shoe in the bellhousing on the boat hold the shift shaft down so the reverse latch works.

There should also be a thin washer and cotter pin that prevents the shift shaft from coming all the way out of the upper housing, are they in place?

 

[Capt Ken]

Re: Taking a Long Shot

The washer was missing but the cotter pin was there. I installed a washer but there is still quite a bit up up and down play in the shaft. Being there is no flat washer on top of the shift shaft seal like a normal outdrive, there is nothing to keep the shaft from going down to far so the spring might help keep it in place.

 

[Don S]

Re: Taking a Long Shot

Got me!

Don't know if you have manual #1 or not, but here is a link to it #01 Eng & Drives 63-73 - Download - 4shared - Don S
I didn't see much on that system, but I also didn't spend a whole lot of time looking. Some in the drive section, and a page (a picture) in the installation section.

 

[Capt Ken]

Re: Taking a Long Shot

Was that the old orange manual that came in two volumes? I still have volume I but loaned volume II to a friend 30 years ago and haven't seen him or the manual since. The PDF showed the setup but didn't explain the workings but I did see several pictures of gimbal housings with reverse lock linkage installed on the back side. Looked like some of the old Mercurys linkage with the wire that picks up a lever that pushes down the lock. Looks like I'm going to have to just engineer something.

 

[Don S]

Re: Taking a Long Shot

Yes, that's the big orange book.

Looks like I'm going to have to just engineer something.

From the looks of that drive, that's not surprising at all.

I wonder if the length of the shift shaft in that long extension housing could be the problem. If it's the wrong height, it's not going to let the cam work right.

 

[Capt Ken]

Re: Taking a Long Shot

Don't think its the length of the shaft, it doesn't have anything to rest on top of like the washer on top of the seal on a regular lower unit. But I don't think its going to work anyway. I think the pressure it will take to push the spring loaded lock down will jam the shift shaft and keep it from turning.

 

[Bondo]

Re: Taking a Long Shot

Ayuh,.... Crazy thought Ken,....

Take that whole lock thing off there, 'n plumb in a new style trim pump, 'n control the kick-up, hydraulically...

 

[Capt Ken]

Re: Taking a Long Shot

Thought about that BUT, the mounting hole under the transom where the lines come through is different. This is a one hose system. Plus the distance between mounting pins on the rams is greater on this one than a two hose ram. Was thinking of that idea before as a way to adjust the angle of the wing that mounts on the underside front of the drive but due to the increased length of the unit, the forces would be too great for the hydraulics to hold. Then any leakage in the hydraulics would result in a wing angle change resulting in the stern rising and possible lost of control.
This whole system is outside the box thinking.