Alpha One reverse/shift problems...

[cadunkle]

I recently got an '89 Marlin with a 260 HP Mercruiser small block Chevy and Alpha One outdrive. Before I got it I tested it on the water with the dude I got it from and whenever I would put it in reverse it would chatter/grind for a second then pop into gear. He said it was normal, I highly doubt that but planned on having to fix that at some point.

Well I fixed a few minor things on the boat and dropped in in the water yesterday only to find that revese wouldn't engage at all. I felt like a prick typing up the ramp while trying to get it working. After a few minutes of fiddling with the adjusting nut for the cable off engine bracket to outdrive I got reverse to engage. The farther forward I put that nut the quicker reverse engages. If I go too far though forward does not work. Where I have it now reverse chatters for a second then engages but forward does not disengage nicely. I have to bring the shifter back past neutral then it'll go into neutral.

I'm hoping it's just an adjustment of the cables. Can anyone tell me how to properly adjust the shift cables? Also, is there any place to download a manual for the engine/outdrive? If not where can I get a decent shop manual?

Also, could this be an internal problem such as a bent shift fork or whatnot? If so I guess I'll just have to get a manual and go through the outdrive this winter. I've rebuilt several manual transmissions and engines so I am mechanically inclined and reasonably knowledgeable. The most I've ever done with outdrives and such is replacing some gears in a old 9.9 Evinrude, so this is fairly new territory for me.

 

[Fishermark]

Re: Alpha One reverse/shift problems...

You might try disconnecting your lower shift cable and see if you can shift it into and out of gear by hand. With the engine off, disconect the cable and push in on the end while someone turns the prop counterclockwise. The prop should lock in place. That is forward.

Then pull on the cable while someone turns the prop clockwise. Again, it should lock in place - that is reverse. If the cable seems stiff, then it needs to be replaced. If it shifts easily, then it may just need adjustment. I BELIEVE this is the manual for your engine:

http://www-alt.mercurymarine.com/mnetdata/SERVICE/CRUISER/Servmanl/15/cover.pdf

 

[cadunkle]

Re: Alpha One reverse/shift problems...

Alright some more information... I took the boat out today and found out som more. After idling for about 30-60 seocnds after warming up the boat would start shaking if not in gear (either forward or reverse). Turns out I had adjusted the shift cable too tight and I think it was trying to engage reverse when the shifter was in neutral. I loosened up the shift cable nut to take up all the slack and just a ahir pas that. Forward works nicely but reverse grinds/cruches. I watched the shift cabes on the bracket as I shift and reverse onoly engage once I've moved the throttle into reverse a good amount.

I have maybe 30* of movement on the shifter into reverse before the shift cable is moved fully into the reverse position, only then will it engage. It seems like if the shift cable would move more quickly to fully engage the gear then there may be no grind. If I move the shifter quickly to where reverse cal be is fully pulled there is a slight crunch and I immediately get reverse.

One evening this week i will try shifting with the cable disconnected and see how it responds. I'll let you know what I find.

 

[Big Del]

Re: Alpha One reverse/shift problems...

Any word on your cable ajustment, and how it turned out.

 

[cadunkle]

Re: Alpha One reverse/shift problems...

I just got home and changed so I can start working on this lower unit. Also gonna check the carb,timing, plugs, etc. as the engine take a couple seconds to start when warm but starts real easy when cold.

Anyhow, I noticed on the outdrive lower unit it says DESTROY on the port side. Paint on hte lower unit is noticeably newer than the upper part of the outdrive. The guy I got it from did say he replaced the lower unit. Just curious as to why it says DESTROY. Maybe an engineering sample or something? I don't imagine Mercruiser would stamp all their drives like that. lol

Anyhow I'll get to working on this thing and let you know what I find.

 

[xltier]

Re: Alpha One reverse/shift problems...

I recently got an '89 Marlin with a 260 HP Mercruiser small block Chevy and Alpha One outdrive. Before I got it I tested it on the water with the dude I got it from and whenever I would put it in reverse it would chatter/grind for a second then pop into gear. He said it was normal, I highly doubt that but planned on having to fix that at some point.

Well I fixed a few minor things on the boat and dropped in in the water yesterday only to find that revese wouldn't engage at all. I felt like a prick typing up the ramp while trying to get it working. After a few minutes of fiddling with the adjusting nut for the cable off engine bracket to outdrive I got reverse to engage. The farther forward I put that nut the quicker reverse engages. If I go too far though forward does not work. Where I have it now reverse chatters for a second then engages but forward does not disengage nicely. I have to bring the shifter back past neutral then it'll go into neutral.

I'm hoping it's just an adjustment of the cables. Can anyone tell me how to properly adjust the shift cables? Also, is there any place to download a manual for the engine/outdrive? If not where can I get a decent shop manual?

Also, could this be an internal problem such as a bent shift fork or whatnot? If so I guess I'll just have to get a manual and go through the outdrive this winter. I've rebuilt several manual transmissions and engines so I am mechanically inclined and reasonably knowledgeable. The most I've ever done with outdrives and such is replacing some gears in a old 9.9 Evinrude, so this is fairly new territory for me.

to check for looseness in the lower unit shift spool,have someone hold the prop against locked position,say forward,and see if you can move the shift cable,after you disconnect it from the shift plate,in and out at all.should be fairly slack free.if there is free play in the cable it could be why you cant get positive engagement in both directions.just a thought.hth