1976 1150 lower unit removal?

[Tduv]

I'm looking to swap out my water pump on my 1976 mercury 1150. I was looking at information about removing the lower unit. Some things I have read were to shift it into reverse before removing? Also, to discontinue the shift linkage I believe? Alothough it looked like the shifter was in the bottome unite when removing from a video I saw. So not sure if I need to disconnect any shifting linkage? Other things I have read were to just lossen the nuts and it will pop out. Just looking for some direction to make this process easy and smooth and make sure I don't botch anything. It seems that the new water pump base I got does not have the screw hole in it for the vent drain plug. Could I still use the new one without it or do I need to reuse the old one?Any advice is greatly appreciated!! Also, can I use parts degreaser to clean it up and then grease it back up?Thanks.

 

[Chris1956]

Put the shifter in neutral. loosen the 5 nuts that you can see. Three on top, two underneath. Then stick a thin wall socket thru the hole above the prop and remove the zinc anode. Remove the bolt under it.

Now wiggle the gearcase down, until you can remove the two nuts on top.

The flush plugs on the waterpumps were discontinued years ago. No need to reuse the old one. If the waterpump base is melted replace it, using new gaskets and oring. If the stainless steel cup is scored, replace the upper waterpump. Always replace the impeller, wearplate and 2 gaskets.

 

[Tduv]

Chris1956 thank you once again buddy!! That's how I thought it would come off. I'm just gonna replace the whole pump as I have a new one. Finally got a weekend that will have about 6 hours of no rain here in Illinois. Got the motor running extremely smooth. Hopefully all they will transfer to the load test tomorrow. Thanks again man!!

 

[Chris1956]

When reinstalling the gearcase, remember to push the gearcase up tight (no bolts), and then turn the flywheel to mate the driveshaft splines. You may need to wiggle the shifter to mate those splines as well. Remember to put a bit of grease on the splines, before assembly.

 

[Tduv]

Took your advice and it works great. Not under load I can't get it to idle. But that's a whole diffrent can of worms

 

[Tduv]

Chris1956. Should the gear case have gone up completely flush without bolts? Or do I put it up there, spin the fly wheel till it pushes up some them get it flush the rest of the way with the bolts? As that is how I had to do it. It shifts fine and the prop spins fine with no noise.

 

[racerone]

It is not a good idea to force it together with the nuts.----When splines are lined up it should slide together all the way.

 

[Tduv]

Back to dropping the lower to get it up there ready then. My help was not much help so tried doing it myself

 

[Chris1956]

They do fit tight, so it is tempting to use the nuts to force it into position. That can ruin the crankshaft or driveshaft.

A better way is to push it up by hand, install some nuts finger tight and then wiggle some more tightening the nuts by hand, as you go. When she is nearly seated (1/4" or less), you can use the nuts+wrench to finish the tightening

 

[Tduv]

Thank you Chris1956. That's actually how I did it and it went up smooth. Just to be safe I'll retry to see if I can get it up there snug without too much help from bolts. Had it out on Saturday and it shifted fine and the new water pump has it pissing like a rhino