Identify hole

[barnyard]

First of all thanks to those who replied to my recent posts. I am 67 years old and recently bought my first boat (93 23' cutty w/ 5.0 and alpha one/gen2 drive).My question is while replacing the outdrive for painting and impeller replace I noticed a hole on starboard side between two top studs completely caked w/ dried mud?
​The other end of channel on rear unit goes to a check valve(appears to be a ball and spring) If I clean this hole of debris is this sufficient to replace unit and run? What is purpose of this passage?

 

[Bt Doctur]

What you are referring to is called a "dribble hole" for gear oil.If your equipped for it the upper housing has a valve that shicks out about a 1/2 inch and self closes when the drive is removed. The ball and spring in the outdrive is the receiver section of the valve.
If you have a res bottle for the gear oil mounted on the engine you should also have the valve ,
page 4B-5 http://www.boatfix.com/merc/Servmanl/14/14b4.pdf

 

[barnyard]

Bt Doctor- thanks for reply. Not sure if I follow you. My boat does not have remote resovoir and #37 valve. I assume this lube passage is non functional then.I can clean and replace unit. correct?

 

[Bt Doctur]

nothing to clean or replace, without the valve in the gimbal housing just mount the drive. The mounting gasket has a hole for the valve, just install that hole on the left side and use the blank side to cover the check ball in the drive

 

[Fun Times]

Thinking it's odd to have the hole clogged with mud type debris and no oil reservoir. Wonder if the plug is missing on the other side of the bell housing where the oil hose connector would go should the oil reservoir been connected.

If no plug then it might be a better idea to leave the debris in place to help keep water from getting near the drive oil side even though the water shouldn't get inside the drive/past the check ball on the drive side....Specially if you turn the gasket around.

Item number 4 in the first link should be the oil passage plug that goes where the oil hose fitting bib connector item number 8 in the second link down would go, http://www.mercruiserparts.com/bam/subassembly/30858/1017/50
http://www.mercruiserparts.com/bam/subassembly/30858/1017/180