1976 Mercury 500 Lower End Removal

Hi everyone,

I did a search but could not find specifics for a 50hp so I thought I would ask ..

I need to replace the water pump/impeller on my motor (Parts are in the mail). I wanted to get a head start last night and I attempted to remove the lower end/gear case. I removed all the bolts/nuts and was able to get the lower end to drop about an inch but it seemed to get hung up on something.

Reading some other posts it could be getting hung up on the water tube that connects to the pump?

I have also read some posts were the shift linkage is mentioned, I did not remove any bolts connected to the shift linkage, is there a separate location where I need to disconnect this? I have looked at some service manuals online but I could not find anything specific.

Does the motor need to be in forward gear to remove the unit or is neutral fine?

Does this motor have a thermostat?

Thanks
Shawn

Re: 1976 Mercury 500 Lower End Removal

The shift lever is splined, could be rusted together if it hasn't been greased by the previous owners. Did you get ALL the bolts out, even the one underneath the anode?

Re: 1976 Mercury 500 Lower End Removal

I believe so, unless the shift linkage is connected somewhere else, I removed 5 bolts/nuts in total , 4 for the gear case and 1 for the trim tab.

I got the two on either side , removed the trim tab to remove the front bolt then the bolt in the center just behind the trim tab .. It did drop down an inch or so enough for me to see the water pump, I just did not want to force it in case I missed disconnecting the shift linkage or something else.

So being in gear or neutral does not matter?

Shawn

Re: 1976 Mercury 500 Lower End Removal

I believe I shifted that motor into forward. Could also be the driveshaft is stuck in the crankshaft. Look at the diagram for your motor, it's a splined male/female setup, it should just drop down from what I'm seeing.

Re: 1976 Mercury 500 Lower End Removal

Thanks, I will take a closer look on the weekend , as long as the shift linkage is not connected somewhere else then it should be free and may just need a little assistance. I picked up the boat/motor last season and it only had a light stream at the tell tale so I am guessing the impeller had not been replaced in a while which it turn means the lower end had not be removed/greased in a while.