Alpha 1 Gen II - Stuck in Forward - Help

The Stern drive on our Mercruiser 3.0L was leaking oil, so we drained the oil and removed the Stern Drive. The upper and lower units were separated. The oil seals in the shift shaft assembly were leaking badly and a new assembly was ordered and installed. The shift shaft was turned clockwise as viewed from the top while turning the prop counterclockwise until it locked. I held the shift shaft in the forward position while a friend lowered the upper drive onto the lower drive. The prop was turned counterclockwise slightly to align the splines and the upper drive seated nicely. While still holding the shift shaft, bolts and nuts were tightened securing the upper and lower unit. While still holding the shift shaft my friend turned the prop counterclockwise to ensure the drive was still is forward. When the prop was turned clockwise a clicking sound could be heard. The stern drive was then mounted, but the prop is locked in forward regardless of the shifter being in forward, neutral or reverse. Also when the prop was turned clockwise there was a faint click, but nothing like it was when the drive was not mounted. We tried this three times and resulted in the same results. I have referenced the service manual for the drive and somewhat mechanically inclined, but have exhausted options and probably missing something.

Any assistance would be greatly appreciated.

Thanks
Tim

Re: Alpha 1 Gen II - Stuck in Forward - Help

If the control moves freely, to no effect then most likely the little wheel on the underside of the upper shift shaft lever is not between the arms of the shift slide at the end of the shift cable. Need put the control in forward, turn the prop CCW till it locks, slide the outdrive back and make sure the wheel is properly captured between the arms and slide it back together. Like ziggy's photo in post #7 here: http://forums.iboats.com/showthread.php?t=458095 Since the slide moves aft when you shift to forward, the wheel is probably in front of the front arm. Good luck.

Re: Alpha 1 Gen II - Stuck in Forward - Help

Did you put the washer back under the shift shaft?

Didn't really read the above post till now but that could be it too. Use a glob of grease to hold the slide in place.

Re: Alpha 1 Gen II - Stuck in Forward - Help

stonyloam and cr2k thanks for your replies.

I have the sterndrive here at home, but the rest of the boat is still up north.

cr2k, The c-clip that fits in the grove locate on the shift shaft is installed. If this what you were referring to?

stonyloam, When the sterndrive was installed, the shift shaft turned counterclockwise(portside) when shifting from forward to neutral, then even more when shifting into reverse. Is this the correct direction the shift shaft should rotate when shifting?

Since only the sterndrive is at home, is it possible to test the shifting. For example, Repeat the steps in my original post, but once the upper and lower unit are mated instead of holding the shift shaft in the forward position, is it valid to move the shift shaft to the neutral position and then check to ensure the prop is free to move clockwise and counterclockwise. Then move the shift shaft in the reverse and check to make sure the prop doesn't turn clockwise (or turns the drive shaft) and clicks when turned counterclockwise. Is this a valid test?

Thanks again for your replies and I hope I'm giving good information in return.

Thanks
Tim

Re: Alpha 1 Gen II - Stuck in Forward - Help


is this what you changed?

this is a counter rotation one, just reverse the F and R

Re: Alpha 1 Gen II - Stuck in Forward - Help

tkdm said:

stonyloam, When the sterndrive was installed, the shift shaft turned counterclockwise(portside) when shifting from forward to neutral, then even more when shifting into reverse. Is this the correct direction the shift shaft should rotate when shifting?

Since only the sterndrive is at home, is it possible to test the shifting.

Click to expand...

So this is a Gen II right? You are correct. Easy to check. Turn the lower shift shaft all the way clockwise, turn the prop counterclockwise, it should lock. If the lower ss points straight ahead then you have it together correctly (like in the Dr's photo which remember is labled incorrectly R is really F). As you did before one position CCW of the shift shaft is neutral and all the way CCW is reverse, prop will lock when turned clockwise. FYI: When you move the control handle from N to F the shift slide moves aft. There are two arms on the shift slide that captures a small wheel on the underside of the upper shift shaft lever and the forward arm pushes on the wheel and rotates the shaft clockwise putting the gearhousing into forward. When you shift back to N or R the slide moves forward and the aft arm pushes on the wheel and rotates the shift shaft CCW. I think your problem is that when you put it back together the wheel was not between the arms and that is was behind the aft arm so that when you shift to F it pushes OK, but when you go back to N or R since the wheel is not captured the slide moves forward, but the ss does not rotate and you stay in F.

Re: Alpha 1 Gen II - Stuck in Forward - Help

Bt Doctur, yes this is the part #35 is what was replaced along with the o-rings. The shift shaft was re-used since there appeared no wear or problems.

stonyloam, I will separate the lower and upper again and get the shift shaft in the proper alignment, mated the upper and lower and then test the forward, neutral and reverse positions.

Just or clarification, When turning the shift shaft CW and the prop CCW the prop will lock in forward. If the shift shaft is not pointed opposite of the prop, Is it OK the continue turn the shift shaft until it is pointed opposite of the prop(or toward the back of the boat if the stern drive was installed on the boat?

As for checking whether or not the wheel was between the two "arms" I will need to wait until next weekend when we go back to the cottage.

I will have some time this weekend and report back with the findings.


Thanks again for you follow-up and guidance.

Re: Alpha 1 Gen II - Stuck in Forward - Help

You should not have to take it apart again, just turn the shift all the wall clockwise till it stops (it will only go so far), and check that it is in forward. If the shift shaft is pointed straight ahead you are OK. If you put the shift shaft back into the shift crank incorrectly it will be way off, like 40 degrees one way or the other, so it is pretty easy to tell. The reasoning behind all of this is that in order to remove or install the outdrive the top of the lower ss must slide freely out of the bottom connector of the upper ss here: http://www.mercruiserparts.com/showSpecialPicture.asp?pn=816685 so both must be pointed straight ahead so they will fit together properly. Pushing the control handle forward aligns the upper ss properly, and turning the lower ss clockwise and locking it in forward should align the outdrive properly.

Re: Alpha 1 Gen II - Stuck in Forward - Help

Well, spent some time this past weekend and could not get what I would expect to be a working lower unit. I was able to get the drive to "lock" in forward, but the shift shaft was not pointed in the direction shown above (clarify R is really forward for my drive Alpha 1 Gen II) but I'm able to continue to rotate it until it is pointing forward. Should the shift shaft be able to turn 360 degrees? If the shift shaft is properly engaged in the shift crank should the shift shaft only have limited rotation? Is there anyway to inspect the shift crank for condition? Is the shift crank a part tha can wear out? Is it made of metal of plastic? Sorry for all the questions, but thought it may help determine if I need to take the drive in for service. Has anyone taken a lower unit apart and back together? Is it something that can be done. Prior to taking the drive off the drive shift perfectly, so wondering if something could have broken, Any possibilities.

If anyone can provide an overview on how the shift crank works(internal pictures, I have the service manual) that would be great.

I like to tinker as well as understand how things work so any help is greatly appreciated.

Re: Alpha 1 Gen II - Stuck in Forward - Help

tkdm said:

Well, spent some time this past weekend and could not get what I would expect to be a working lower unit. I was able to get the drive to "lock" in forward, but the shift shaft was not pointed in the direction shown above (clarify R is really forward for my drive Alpha 1 Gen II) but I'm able to continue to rotate it until it is pointing forward. Should the shift shaft be able to turn 360 degrees? If the shift shaft is properly engaged in the shift crank should the shift shaft only have limited rotation? Is there anyway to inspect the shift crank for condition? Is the shift crank a part tha can wear out? Is it made of metal of plastic? Sorry for all the questions, but thought it may help determine if I need to take the drive in for service. Has anyone taken a lower unit apart and back together? Is it something that can be done. Prior to taking the drive off the drive shift perfectly, so wondering if something could have broken, Any possibilities.

If anyone can provide an overview on how the shift crank works(internal pictures, I have the service manual) that would be great.

I like to tinker as well as understand how things work so any help is greatly appreciated.

Click to expand...

It should not rotate. It's movement should be limited to the movement shown in the drawing. How it works? I'll give it a try. Look at this drawing: http://www.mercruiserparts.com/Show...c=GEAR+HOUSING(PROP+SHAFT)(STANDARD+ROTATION)
#39 is the shift crank (click on hipertext to see photo) it fits into the shift spool assembly #40 (look at the photo to see where it fits into the grove, I think) and when the shift shaft turns it turns the crank and slides the shift spool and the gears #43 F and #49 R so that they engage the gear on the bottom of the driveshaft and that causes the propshaft to either rotate clockwise or CCW. I suspect that the crank is not properly captured by the shift spool The slot shown here http://www.mercruiserparts.com/showSpecialPicture.asp?pn=818349T1 That is my best guess.

Re: Alpha 1 Gen II - Stuck in Forward - Help

Thanks again for your comments. It concerned me that I was able to rotate the shift shaft 360 degrees. From previous experimentation I noticed that if I positioned the lower unit with the prop pointed upward the prop was locked into forward. Your comments gave me the idea to position the lower unit with the prop down. I then installed the shift shaft which result in the shift shaft having limited rotation as you explained. The shift shaft wasn't pointing correctly, so I loosened the screw on the shift shaft assembly and positioned it correctly and tighten the screws. Not sure why this worked, but thought there may have been something out of "alignment" which prevent the shift shaft for engaging the shift crank or something. In the end the issue is resolved and I thank you for offering advice. Without it I would have taken it in for service eventually and probably would have been taken for a ride.

Re: Alpha 1 Gen II - Stuck in Forward - Help

Great! I'll bet that when you loosened the screw and repositioned the shaft the crank dropped into the shift spool in the proper position. The crank is held on top by the shift shaft and the bottom by a small shaft, guess the bottom of the crank could have not been properly seated on the shaft and it went back together correctly when you loosened it up. Anyway have fun.