what kind of drive is this? And why wont it shift to reverse?

[AChettle]

I think its an Alpha 1 Gen 2... But I could be wrong. This is my first boat and my first post. I am a newbie to the boat world, so please be gentle. I have this drive (see posted pics) and even if I disconnect the lower shift cable from the interrupt switch plate, and pull it as hard as I can, it still will not engage the reverse gear. I pulled the drive off and I was able to engage the reverse gear by turning the shift shaft thingy. So, I changed the lower shift cable, and it still does the same thing. what would prevent the lower shift cable from pulling out enough to engage the reverse gear?

 

[Bt Doctur]

Re: what kind of drive is this? And why wont it shift to reverse?

Nope, called a MC1. a rusry splined shift shaft or a worn shift spool for starters

 

[Faztbullet]

Re: what kind of drive is this? And why wont it shift to reverse?

Thats a old I drive from the middle 70's to very early 80's.

what would prevent the lower shift cable from pulling out enough to engage the reverse gear?

Which cable style did you install?(cut or no cut? Aft or forward install?) Problem could be shift arm hanging on support tube, imprper installation,worn splines on intermediate shift shaft or shift spool in lower unit is worn from water intrusion.

 

[haulnazz15]

Re: what kind of drive is this? And why wont it shift to reverse?

Definitely an MC-1. I'd be checking to ensure the intermediate shift shaft is securely inside the "foot" of the upper shift shaft. If you are able to put it in reverse by hand, the problem is likely somewhere between the intermediate shift shaft and the shift bracket. Does the intermediate shaft point straight forward when in fwd gear? If it is bent/twisted, that could prevent the shift cable from being able to adjust far enough to engage reverse.

 

[AChettle]

Re: what kind of drive is this? And why wont it shift to reverse?

Thanks Guys, for identifying it for me.

haulnazz15:
The shaft points straight (12:00) when in the forward gear, however, I did notice that the very same shaft has a lot of play in it. Almost an 1/8" of play when I wiggle it. Is this the sign of a worn bushing inside?

Faztbullet:
The cable I installed was a braided steel cable and a little steel tube that goes on the shift plate end? (Came with the boat).
As far as aft or forward install... I pulled the drive off, yanked the old core wire out, slid the new one in, reinstalled the drive. whatever you call that, that's what I did.

I'm going to see if I can find an exploded view of this drive so I can better understand some of the nomenclature, as I am not too sure of the names of all the components, or how this system works. If I could see inside, maybe I can get a better understanding of what's going on.

 

[achris]

Re: what kind of drive is this? And why wont it shift to reverse?

It's difficult to see in the photos, but I believe we have a 'frankenmerc' here. The drive-shaft housing ('upper') is most definitely an MC-1, but the trim rams are not, they look to be MR/Alpha One, as does the gear housing ('lower'). I also think I can see that the bell-housing has a flat top, again suggesting an R, MR or Alpha One.

One thing it is definitely NOT is an Alpha One Gen II...

Chris........

 

[Bondo]

Re: what kind of drive is this? And why wont it shift to reverse?

Thanks Guys, for identifying it for me.

haulnazz15:
The shaft points straight (12:00) when in the forward gear, however, I did notice that the very same shaft has a lot of play in it. Almost an 1/8" of play when I wiggle it. Is this the sign of a worn bushing inside?

Faztbullet:
The cable I installed was a braided steel cable and a little steel tube that goes on the shift plate end? (Came with the boat).
As far as aft or forward install... I pulled the drive off, yanked the old core wire out, slid the new one in, reinstalled the drive. whatever you call that, that's what I did.

I'm going to see if I can find an exploded view of this drive so I can better understand some of the nomenclature, as I am not too sure of the names of all the components, or how this system works. If I could see inside, maybe I can get a better understanding of what's going on.

Ayuh,.... Welcome Aboard,... That's Not installin' a new lower shift cable,...

Installin' a new lower shift cable includes the Whole, Complete cable, inner, 'n outer casin',...

The outer casin' gets a groove worn in it, 'n ya loose travel to the internal wear,...

 

[AChettle]

Re: what kind of drive is this? And why wont it shift to reverse?

Ayuh,.... Welcome Aboard,... That's Not installin' a new lower shift cable,...

Installin' a new lower shift cable includes the Whole, Complete cable, inner, 'n outer casin',...

The outer casin' gets a groove worn in it, 'n ya loose travel to the internal wear,...

Is there a way to determine if the cable's outer casing needs replacing? The core wire slid out and back in effortlessly. I only changed out the core wire because I thought it might be stretched, as I had some shift interrupt issues late last season.

achris:

Is there a better perspective I could photograph that would help you determine what this thing is? I can also upload higher resolution pics too, I reduced them for webpage speed, but if I knew what you wanted to see, I could take a couple of good shots for you.

 

[Don S]

Re: what kind of drive is this? And why wont it shift to reverse?

Bigger pictures would sure help. What year is the boat? Any engine serial numbers.

Bigger pictures of the area in yellow.

 

[achris]

Re: what kind of drive is this? And why wont it shift to reverse?

Is there a way to determine if the cable's outer casing needs replacing? The core wire slid out and back in effortlessly. I only changed out the core wire because I thought it might be stretched, as I had some shift interrupt issues late last season.

A 'stretched' cable will only cause an out-of-adjustment problem. And removing the cable from the shift plate and pulling it would negate any stretch. If you're pulling the cable manually and still can't get reverse, I suggest your problem is something other than the shift cable. A few things to check. Dirt and crud in the back of the shift slide cavity in the bell-housing, accumulated dirt inside the slide itself, worn fingers on the slide, a worn/missing/damaged roller on the arm (also in the bell-housing), too much rotational movement between the bottom of the upper shift shaft and the top of the intermediate shift shaft (where the 'shoe' slides in) or worn splines in the bottom of the intermediate shift shaft and the top of the lower shift shaft....

achris:

Is there a better perspective I could photograph that would help you determine what this thing is? I can also upload higher resolution pics too, I reduced them for webpage speed, but if I knew what you wanted to see, I could take a couple of good shots for you.

The best shots would be about a yard (3 feet) from the gasket between the drive and the bell-housing, back above and behind. And a shot (again about a yard back) from directly behind where the drive-shaft housing meets the gear housing (where that stupid 'wing' is). Also a shot of the very end of the prop shaft (close up if you can maintain the focus, I'm looking for a letter stamped in)...

Cheers...

 

[AChettle]

Re: what kind of drive is this? And why wont it shift to reverse?

Okay, so I'll pull the drive off again and check for any dirt/obstructions in the cable cavity, and/or roller issues that might impede the travel of the cable. This sounds like the easiest and least expensive thing to do. (Here's hoping it's something that simple).
As for I.D. photos, here's some better ones:

 

[achris]

Re: what kind of drive is this? And why wont it shift to reverse?

ok.. The bell-housing is 'squared off', the contours don't quite match the front of the drive-shaft housing. Also the gear housing is the same, squared off where it meets the drive-shaft housing (4th photo). This indicates the bell-housing and gear housing are from the R/MR/Alpha One series. Also the trim rams (which have the end cap seal damaged BTW) have external return lines, so are from this later series too. The drive-shaft housing is most definitely an MC-1, by both shape and serial number. If you can find the serial number on the transom assembly we could find out exactly when that is from. Unfortunately the gear housing will be a little harder to nail down. I was looking for the letter 'A' to be stamped in the end of the propeller shaft. Had it been there, it would have identified it as an early MR. So without it, it can still be R/MR/Alpha One. When you split the drive for a water pump service we can get a bit closer. If the drive-shaft has a spring-loaded pin in the top of it, it's an R, if no pin it will be either a (later) MR or an Alpha One.

One more thing. As the drive-shaft housing has been changed (at some stage in the past, probably due to either destroying the gear through lack of oil, or the yoke seal leaking), check the drive overall ratio. Also, if you have an engine serial number that might also help identify the original parts of the drive....

Chris.....

 

[AChettle]

Re: what kind of drive is this? And why wont it shift to reverse?

A 'stretched' cable will only cause an out-of-adjustment problem. And removing the cable from the shift plate and pulling it would negate any stretch. If you're pulling the cable manually and still can't get reverse, I suggest your problem is something other than the shift cable. A few things to check. Dirt and crud in the back of the shift slide cavity in the bell-housing, accumulated dirt inside the slide itself, worn fingers on the slide, a worn/missing/damaged roller on the arm (also in the bell-housing), too much rotational movement between the bottom of the upper shift shaft and the top of the intermediate shift shaft (where the 'shoe' slides in) or worn splines in the bottom of the intermediate shift shaft and the top of the lower shift shaft....



The best shots would be about a yard (3 feet) from the gasket between the drive and the bell-housing, back above and behind. And a shot (again about a yard back) from directly behind where the drive-shaft housing meets the gear housing (where that stupid 'wing' is). Also a shot of the very end of the prop shaft (close up if you can maintain the focus, I'm looking for a letter stamped in)...

Cheers...

Sorry I took so long getting back, I'm currently working out of town and didn't have much time to play with the boat. It looks like achris was correct. I pulled the drive off and noticed that the "shoe" on the bottom of the upper shift shaft (the "U" shaped thing that the "foot" slides into) was allowing lots of play in the connection made with the top of the intermediate shift shaft. The solution: a pair of vise-grips to squeeze the "U" so it makes a snug connection to the intermediate shaft. I closed it to allow 1/16" of play between the 2 shafts. The boat now shifts perfectly.
Thanks for all the help guys.

Aaron

 

[Eric 3.7LX Alpha 1]

Re: what kind of drive is this? And why wont it shift to reverse?

That part gets damged when people remove the drive without putting the remote shifter in forward, so it's facing straight.