Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

[glennj3]

Finally got around to pulling the lower unit apart, decided to check the water impeller while it is off. Needed replacing of course after only 4 times in the water last summer.

From a previous thread, my shifter stopped going into reverse (would not move very much backwards). I know the shifter needs to be in forward then join up the lower unit with the water connecting pipe in place. Problem is my lower unit is in forward if I am not holding it in neutral. I am not sure of the sequence of putting her back together.

I don't know the name of all the little parts up there but I can explain as best I can. I have the shifter shaft with the star teeth in the upper outdrive, it joins into the shifter in the bottom part. But if the shift shaft is not in the correct position when joining up with the shifter cable in the outdrive, the shift handle will not work correctly.
So do I leave the lower unit in forward, shift handle in forward, start putting it together with the upper, position the shift shaft into the slot with the shifter, then slide it into the shifter coming from lower unit?
Tighten everything up then check the for correct gear adjustment?

Sorry for the poor ID of parts.
Glenn

 

[Bondo]

Re: Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

So do I leave the lower unit in forward, shift handle in forward, start putting it together with the upper, position the shift shaft into the slot with the shifter, then slide it into the shifter coming from lower unit?
Tighten everything up then check the for correct gear adjustment?

Ayuh,.... Keep Everything in forward during assembly, 'n it'll work properly....

 

[glennj3]

Re: Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

Thanks Bondo !!

 

[ziggy]

Re: Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

agreed with bondo (who taught me). keep everything in fwd.
to help keep the lower in fwd. put a bungee cord on the prop and load it ccw. if you move the prop shaft even the smallest amount, the lower will likely come out of fwd. unless ya move it ccw, which then will move the drive shaft in the lower which may have to move to align the splines of the lower drive shaft and the driven shaft in the upper.
fwiw. assembling the lower to the upper is a much much easier job with the drive on the bench. + ya get to do other pm while the drive is off. ie. lub coupler, lub ujoints, check alignment, check drive shaft bellows, etc.

 

[achris]

Re: Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

I don't kow why everbody talks about using a bungee cord. I have never used it, and never needed to. If the upper is still on the boat and you're just putting the lower back on it, put the control in forward and lower in forward. As you are positioning the lower into the upper with it tilted up, the shift spool in the lower will naturally want to move to the forward position (gravity)... just rotate the prop slightly CCW as you slide it up and the splines will engage....

Chris........

I have to check my impeller in the next week or so. As I have had the drive off recently I will not be pulling the whole unit, just dropping the lower. I will make a video of the job and submit it. If you've looked at my previous videos you'll see no bungee cord when I put the drive back on either....

 

[glennj3]

Re: Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

Thanks, I plan to leave the upper unit on the boat, will just replace the impeller, ( I noticed one thing, if I turn the shaft on the lower unit, thus turning the prop, the impeller turns in the correct direction, but if I turn the prop with it in the same forward gear, the impeller will turn backwards, stressing the impeller). Not that it will turn attatched to the upper, just a note on interest in case someone spends some time turning the prop while detatched from the upper!
The lower goes into forward gear and stays there, I can only hold it in neutral or reverse, soon as I let go, it moves itself into forward!
Hope to get on it this weekend.

 

[glennj3]

Re: Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

Why is the impeller so difficult to pull off the shaft? I had to use a crow bar to pry it off (same thing last year). I used Emory cloth to polish the shaft and put grease on it while replacing it. I would like to do something to it so it will not be so difficult next time.
I did order the impeller through this site, cheapest one anyplace !!

 

[achris]

Re: Old story, replacing the lower out drive correctly, 1988 Alpha I Mercruiser

Did it have a brass hub or fibre?