Lower cover nut removal on a '72 7.5hp mercury

[jasunderland]

Is there a trick to removing this without the tool or do I need the tool? I'm trying to remove the drive shaft to see if it is pitted badly because I'm getting water in my oil with minimal running. I checked the drain and vent plugs already.

The manual says I need to remove the bearing carrier and propeller shaft to remove the drive shaft but I'm stuck on how to remove the cover nut without a tool. I've tried heat and I have it soaking in penetrating oil. I've tried a punch and hammer but it is dinging up the nut and not budging.

 

[Scott Danforth]

Get the tool to pull bearing carrier and prop shaft However most of the vertical driveshaft is visible if you just drop the foot

 

[GA_Boater]

Drop the lower unit and pressure test before trying to tear it apart. Other than the fill/vent gaskets, there are three places for water to get into the lower unit. Seals under the water pump, shift shaft seal and the prop shaft seal. Pressure test with soapy water and look for bubbles.

Stop beating on the parts, you won't get it apart like that.

 

[jasunderland]

Drop the lower unit and pressure test before trying to tear it apart. Other than the fill/vent gaskets, there are three places for water to get into the lower unit. Seals under the water pump, shift shaft seal and the prop shaft seal. Pressure test with soapy water and look for bubbles.

Stop beating on the parts, you won't get it apart like that.

I already did this. No need for soapy water as air was just pouring out for right above the water pump where the driveshaft goes through. I talked to a local Marine guy, and he said that the old Mccree driveshafts would get pitted and there was no good way to get them sealed again. Looking at it though, I'm not sure that it is that bad. I kind of wanted to Get the driveshaft out so I could clean it up real good and verify. Who knows, maybe it's just a bad seal inside the water pump.

 

[Scott Danforth]

pull the water pump. you can see the whole shaft down to the top bearing (water pump housing is the top bearing seal) no need to pull shaft

Get the complete kit. if your driveshaft is 0.438" in diameter, Sierra 18-3447, if the driveshaft is 0.456" in diameter, Sierra 18-3446