Re-Installing Lower Unit

Randy22

Seaman Apprentice
Joined
Jul 26, 2007
Messages
45
I just finished dropping my lower unit on my Mercury 200HP Offshore and replacing the water pump. A local tech told me to put the throttle in forward before I took the unit off. When I replaced water pump and attempted to put the lower unit back on, had issues getting it to line up. After a bit of shaking it went up enought for me to put two of the bolts on and then tighten it up. After getting everything back together and tighten, I got into the boat to crank the motor to see how my work did, the motor would not go into netural so I could crank. After some resistence, it cranked but it was also in gear. Did I not line the gear shaft up and could it have possibly jamed. I assume I need to drop the unit again but before I do, I'm looking for some ideas on what the problem may be. Did I need to put in forward or would netural have worked? Been a while since I was on the forum so could really use some help to resolve this pain. Thanks.

Randy
 

Prophammer

Chief Petty Officer
Joined
Jul 2, 2010
Messages
466
Re: Re-Installing Lower Unit

It won't go into reverse or neutral? When you bolted it up, did you make sure to draw it up evenly, crossing back and forth side to side? If not it could be in a bind because of that, either way, I would take it back off and try it again. I'm not sure about that forward thing even though I put mine on like that, with it in forward, but my shift shaft had to be jiggled somewhat to get it to engage, then I wiggled the foot up enough to start bolts
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: Re-Installing Lower Unit

I always put a little never seize on the upper splines of the drive shaft when reinstaling inorder to keep the corrsion from seizing that fitting. Makes it easier to remove the LU again if needed.
Oldman570
 

Randy22

Seaman Apprentice
Joined
Jul 26, 2007
Messages
45
Re: Re-Installing Lower Unit

Won't go into nuteral or reverse. Can really feel the resistance. Bolted it back on evenly but as I mentioned, had a lot of trouble lining it up bit once it slipped up enough to expose the bolt threads, it bolted on firmly. Going to drop foot agian and see what happens. Just concerned what gear the foot shaft is in vs. throttle linkage shaft since the prop spun. I assume that tells me it is in forward but also wonder how it cranked in forward.
 

Randy22

Seaman Apprentice
Joined
Jul 26, 2007
Messages
45
Re: Re-Installing Lower Unit

OK...just dropped lower unit again. Go to console and shifts freely into nuteral reverse, etc. so all that is good. How do I know what gear the lower unit is in? Would I assume that shaft turns three ways with it being in forward at say 3:00, neutral at 12:00 and reverse at 9:00? Or something to that effect. Just need to know how to match throttle (gear) with lower unit gear as obviously the last time I had a mis match. I had to turn gear shaft clockwise to get impeller in, so would that have had any effect on alignment? Can you tell from direction that the prop turns when disconnected from engine? Thanks in advance for the help.
 

westexasrepublic

Chief Petty Officer
Joined
Jun 17, 2009
Messages
524
Re: Re-Installing Lower Unit

neutral will spin freely, in forward it will ratchet clockwise and not move counter clockwise. in reverse it will ratchet counter-clock wise and not move in clock wise.

of course match the gear case to the lever. meaning if you find out the lower unit gear case is in forward then move your shift lever in forward then reinstall
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: Re-Installing Lower Unit

Randy, Turn the lower shift shaft CCW until it snaps into neutral. Set the control for neutral tilt motor all the way up and reinstall the gearcase. Use needle nose plier to mate upper and lower shift shafts. Turn the flywheel with left hand to mate driveshaft and crankshaft. Use fingers only, to tighten nuts. using tools can force damage to crankshaft or driveshaft splines.
 

Randy22

Seaman Apprentice
Joined
Jul 26, 2007
Messages
45
Re: Re-Installing Lower Unit

Guys...all I can say is "awesome". Both engines are now back together with the help of all of you on this thread. Found neutral and the splines lined up perfectly and lower unit slipped all the way up as it should. Cranked both engines and had a 3 foot pee coming out the rear. Engaged both in forward and reverse and they worked great. So, 2 water pumps kits $96.00; 4 thermostats $50.00; tube 2-4-C Grease $9.00; good forum and people willing to help...priceless! Thanks guys. Randy
 
Top