Help needed, pulling and re-installing ’67 100 hp lower unit

[boatman]

Hi all,

Really need some help with pulling and re-installing ’67 100 hp lower unit. Have removed the 6 nuts on the studs to the lower and removed the 2 bolts from the 5" extension into the mid-section. Lower unit slides down and will come off but the wire harness to the gearcase is still connected. Where to I disconnect the wiring going to the gearcase? Anything else I need to be aware of.

Got this far and tried to put it back together, but something is not allowing the lower to slide together. Water tubes are going into the grommets so that is not the issue. I assume the drive shaft splines are not aligned but don’t see a way that I can rotate it to line them up.

Have a dozen 3-40 hp motors. First time working on a big V4 and not familiar with them.

Wanted to replace the impeller and was hoping to hit the water tomorrow. One of the last days I have free for the next three weeks. Trying to get the boat on the water for the first time and give my girls a ride before we loose the mild weather here in Chicago.

Really appreciate the help!

Paul
312-933-0600

[fleetwin]

Paul
Be very careful, you don’t want to break the shift leads/harness. You will find the electric shift harness/cable coming out of the inner exhaust housing in the lower motor pan. This harness/cable must be disconnected before removing the gearcase. You will see the two black rubber tubes covering the knife connections on the shift harness/cable. Grab each rubber tube with needle nose to stretch it slightly so you can spray WD40 in under the tubes, then gently slide the tubes up toward the motor harness so the knife connections can be disconnected. Please be very careful, don’t cut/break those leads! Once the shift leads are disconnected, tie some twine/string onto the gearcase end of the shift cable which will act as a snake when reinstalling the gearcase. Spray some WD40 onto the ribbed portion of the leads sticking out of the exhaust housing which will help lube the ribs allowing them to be pulled down out of the exhaust housing. Once the gearcase is down, you will need to cut the twine/string leaving it in the exhaust housing to be used as a snake during reinstallation.
Again, please be very careful, you are in big trouble if you break that shift cable harness! It is best to have an assistant help remove/reinstall the gearcase.
The crankshaft/driveshaft splines are probably not lined up now, keeping you from reinstalling the gearcase. Have an assistant rock the flywheel back and forth (key off, battery disconnected), the gearcase will pop up into places once the splines line up.

[boatman]

Fleetwin,

Thanks for the quick response. I didn’t pull down on the harness, so should be good there. I think I’ll just put it back together and do the impeller in next month. It pumps water well out of the tell-tale. Have not run this motor much and wanted to change the impeller to be on the safe side.

Thanks for your help!

Paul

[boatman]

Fleetwin,
Got it seated by jiggling the flywheel. Thanks for the tip.
Paul

[Author]

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