No Reverse after water pump change on alpha one lower unit

gregk101

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Recently purchased 1990 Maxum with 5.0LX Mercruiser. Engine is 1989 model. I have changed out the water pump and already before I did this change, the shift cables were stiff and hard to move, so I knew it had issues already, but it did go in both forward and reverse with some effort (boat sat for two years inside garage). Now, after putting the gear housing back on, the forward works as it should, but will not go into reverse. Is this likely a problem with the shift cable or is it possible I messed up the install of the gear housing. My novice thought is that since forward works ok, then the gear housing should be installed correctly. Thanks in advance.

Greg
 

stonyloam

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Re: No Reverse after water pump change on alpha one lower unit

Need a little more info here, but can make a guess with a couple of ifs. If you have a Alpha I (not a gen II), if you only removed the gearcase (lower) and not the whole outdrive, and if the control handle is jammed. Then the gearcase was in reverse , not forward when you put it together and the intermediate shift shaft went on "off a spline". Do this: Drop the lower, rotate the lower shift shaft all the way clockwise, rotate the prop counterclockwise till it locks and hold in place with a bungee, you are now in forward. Move the control handle forward to WOT. Put it back together and you should be OK. If you need to turn the prop to line up the driveshaft splined, turn CCW only.
 

Fishermark

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Re: No Reverse after water pump change on alpha one lower unit

Another guess - and it is a common problem - is you forgot the stainless steel washer that sits on top of the lower shift shaft. Without the washer, the intermediate shaft drops down too far and you cannot shift.

shiftshaftwasher.jpg
 

gregk101

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Re: No Reverse after water pump change on alpha one lower unit

OK. I dropped the lower unit, turned shift shaft CW, moved prop CCW till it stopped, and used bungee cord to hold into position. Put it all back together. The gear shift was in full forward position during all of this work. I tried to pull gear shift back to neutral, and it stops just short. also, when turning the prop it obviously not correct as it is not smooth and makes small clunking noise.
 

gregk101

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Re: No Reverse after water pump change on alpha one lower unit

Just removed the lower unit again. Confirmed that rubber washer and stainless washer are installed. Question: I assume that the shifter should move freely at this point? If so, mine is not, as it will not move to reverse position at all. I have attached some pictures, I noticed that the shift shaft is not straight, with shift in full forward position. Getting fed up with this thing already. Any help would be extremely appreciated IMAG0558.jpgIMAG0563.jpg
 

stonyloam

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Re: No Reverse after water pump change on alpha one lower unit

Did you remove the entire outdrive at any point? If you did, the roller on the shift shaft lever may have slipped from between the arms on the shift slide and be jamming. sounds like you had the lower right. Drop the lower again and see if the control works freely.
 

NHGuy

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Re: No Reverse after water pump change on alpha one lower unit

To answer your earlier question, the shift should move easily when the drive is off the boat. If it's stiff it will need addressing.

In your picture it appears that the shift shaft coupler "shoe" isn't straight. That's the inverted u shaped connector that's supposed to slide onto the drive unit coupler "foot". It's on the bellhousing which the drive attaches to. If you or the previous owner shoved too hard with the shift couplers imperfectly aligned, it may have caused the shift shaft to bend.

With the drive off the boat shift (the drive) with the lower unit shift coupler "foot". It pivots between straight ahead, call it 6 oclock, for forward, and held counterclockwise at around 4 oclock for reverse, with neutral right between the two. If you hold the shift foot on the drive in a clockwise direction it should stop at 6 oclock. If it stops elsewhere, like maybe 7 or 8 oclock, you are on the wrong spline. To fix that you need to split the case and reset the foot on the lower shaft.

"OK. I dropped the lower unit, turned shift shaft CW, moved prop CCW till it stopped, and used bungee cord to hold into position. Put it all back together. The gear shift was in full forward position during all of this work. I tried to pull gear shift back to neutral, and it stops just short. also, when turning the prop it obviously not correct as it is not smooth and makes small clunking noise."

This is all OK, once you take off the bungee it will slip out of forward, the clunking isn't an issue either. Don't sweat that right now.





Once you can feel it shift you can use the prop to assure gears are engaged. When in reverse it will clack and might slip if you turn the prop counterclockwise, but it will hold when you turn the prop clockwise. In forward it will slip CW and hold CCW. Probably will ratchet a bit if you turn it CW while in forward. That's normal with the engine off.
You already did a good install, don't quit now. Once you have the shifter, cable and boat parts working put the drive in forward and bungee the prop CCW to hold it. This holds forward, and importantly, it keeps the coupler shoe straight ahead so you can install the drive.

When things are correct the couplers (shoe and foot) slip together as the drive is put on the boat.

But if that shift shaft isn't straight you might need to deal with it. If it's crooked it might be causing part of your shift bind. If you can have someone shift it at the control while you watch the bellhousing side of the coupler (the shift shoe) it might tell you.
Move the shift yourself too while the drive is off the boat. It will be good to know how much resistance is in there before you put the drive on. As I said at the top if it's not smooth that will need addressing.

Then, once you put the drive on, remove the bungee, wiggle the prop a bit to allow the gears to go slack, and shift to neutral. Try forward, neutral and reverse without running the motor. At each position make sure that the prop does the right thing.
In forward it won't turn counterclockwise.
In neutral it will turn freely.
In reverse it won't turn clockwise.

Hope this helps.
 
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gregk101

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Re: No Reverse after water pump change on alpha one lower unit

Terry - I have not removed the entire outdrive, only the lower unit.
 

stonyloam

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Re: No Reverse after water pump change on alpha one lower unit

Terry - I have not removed the entire outdrive, only the lower unit.

Dang! Sounds like you had everything right. So if it does not move freely with the lower off, you have a shift cable problem, or control problem. Disconnect the shift cable (port side of the engine) and see if you can move the cable by hand, and try to work the control. Should tell you where the problem is.
 

gregk101

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Re: No Reverse after water pump change on alpha one lower unit

Ordered shift cable kit. Took off the drive and the shift cable looks like this. This is my first shift cable replacement, so any short cuts or suggestions would really be appreciated. I have the #6 manual.shift cable.jpg
 

Bondo

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Re: No Reverse after water pump change on alpha one lower unit

Ordered shift cable kit. Took off the drive and the shift cable looks like this. This is my first shift cable replacement, so any short cuts or suggestions would really be appreciated. I have the #6 manual.View attachment 227885

Ayuh,.... Welcome Aboard,..... Ya don't need the extra long socket mentioned in the manual,...

Just cut the end off the old cable to turn it out,...
'n the new cable, the little piece of cable liner, unscrews to install the cable housin',...
Then ya screw it back in, 'n install the inner cable,...
 

crazy charlie

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Re: No Reverse after water pump change on alpha one lower unit

OK. I dropped the lower unit, turned shift shaft CW, moved prop CCW till it stopped, .

This step is correct HOWEVER the shift spline needs to be turned and held in position while you are locking the lower into FWD gear by CCW movement of the prop.I didnt see where you mentioned that step.I dont think your lower is 100% engaged in full fwd.Charlie
 
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