Logo
FULL SITE MENU

Problem assembling lower gearcase to upper unit, alpha-1

L

Larrycruzen

New member
I am replacing the lower gearcase on my MerCruiser Alpha one outdrive. The gearcase consistently hangs up 9/16 inch before seating against the upper unit. I've tried rotating the shaft to align the splines, but that doesn't help. I suspect the water output tube is What is hanging it up, but can't see up in there. Any suggestions?

Larry Cruzen
 
OK, drop the lower and using your finger smear a little grease on the water inlet rubber in the top cap, install guide tube. pour some soapy water to lubricate the impeller , lock drive in FWD gear by turning the prop CCW while turning the splined shaft CW .Try not to move the prop. insert lower and line up copper water tube in guide tube. push drive up, turning the prop CCw about an inch to line the splines up,
Heres the tricky part, install the front nut by a few threads to hold the lower in place. align the upper brass shoe with the lower splined shaft in a straight line bow to stern. push drive up and hand tighten the nut some more. Install side nuts and tighten them carefully watching the shoe so it dosent bind up and make sure in goes into the upper half.Tighten side nuts fully, install remaining nuts, trim tab AND OIL
 
Bt Doctur said:
OK, drop the lower and using your finger smear a little grease on the water inlet rubber in the top cap, install guide tube. pour some soapy water to lubricate the impeller , lock drive in FWD gear by turning the prop CCW while turning the splined shaft CW .Try not to move the prop. insert lower and line up copper water tube in guide tube. push drive up, turning the prop CCw about an inch to line the splines up,
Heres the tricky part, install the front nut by a few threads to hold the lower in place. align the upper brass shoe with the lower splined shaft in a straight line bow to stern. push drive up and hand tighten the nut some more. Install side nuts and tighten them carefully watching the shoe so it dosent bind up and make sure in goes into the upper half.Tighten side nuts fully, install remaining nuts, trim tab AND OIL
Click to expand...

Thank you very much for the reply. I'll try again in the morning. I already have the trim tab installed in the lower gear case .... Is that a problem? Does the water guide tube slide over the rubber in the top unit? I don't understand the following "...watching the shoe so it doesnt bind up and make sure in goes into the upper half." Are you talking about the shifter shoe in the upper half?

Larry Cruzen
 
http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf click the link, then click the main box, then the sections.
shiftshoes.jpg
the lower half goes on the splined shaft .when installing a lower you have to make sure the splines line up ,then as you raise it and tighten the nuts to make sure it "fits" into the upper one . If you miss and try to force it on you bend the "C" arm in the lower unit.And thats a full disassembly to repair.
 
Got it together this morning!! Problem was that the water guide tube kept falling out of the top of the water pump, so the water tube didn't seat into the pump.

appreciate the help.

Larry Cruzen
 
Back
Top