Mystery hole in Bravo 1 gimbal

[Galvez83]

Evening folks
I recently bought a used Bravo 1 gimbal because the one on the boat i purchased is far too gone in regards to corrosion. I prepped and painted the new to me gimbal upon assembly i noticed a hole with some threads that my old gimbal does not have. Can anyone shine some light as to what that hole is for. It is located on top of where the shift cable bellow clamps to in the gimbal housing and below where the grease travels from the grease fitting to the gimbal bearing attached please find a pic of the hole in question front and back of gimbal.

Also, due to my limited knowledge how do i know for certain that my gimbal housing is truly a bravo and not an alpha?

 

[Fun Times]

Evening folks.

Also, due to my limited knowledge how do i know for certain that my gimbal housing is truly a bravo and not an alpha?

The hole is drawing a blank at the moment....Is there by chance a transom assembly serial number anywhere on it?

Also an you post an overall photo of the transom assembly?

 

[Galvez83]

The hole is drawing a blank at the moment....Is there by chance a transom assembly serial number anywhere on it?

Also an you post an overall photo of the transom assembly?

This is the only thing it has i believe it reads D419977

 

[Fun Times]

Yes thanks, that number 0D419977 is coming up as an 1990 MERCRUISER BRAVO TRANSOM BRAVO TRANSOM model number 6020000CR.

I'll look around to see if I recall what the hole was used for if it was stock....That mentioned it may have been added by someone for something...You may have to size it up for the thread type/size, etc. to plug it.

Here's the parts catalog for it, https://www.mercruiserparts.com/bravo-one-0b664190-thru-0f729999

 

[Fun Times]

Looks like it was the early style location for the mercruiser water pitot tube fitting (speedometer) before they moved it up in the top right side if you're looking at it from the inside of the boat looking back.

Here's an illustration of the fitting from 1990, http://boatinfo.no/lib/bulletins.html#mercruiser-service-1990_14

Should need item #'s 28 and 29 but it's possible your original one may fit, https://www.mercruiserparts.com/bam/subassembly/30966/952/60

Here's an illustration of the new location...Upper right with the chrome fitting with white tip, Red Loctite,

What year or serial number was your original transom housing ?

 

[Galvez83]

The boat itself is a 1993 Sea Ray but all numbers to the sterndrive and gimbal have faded away.

 

[Fun Times]

The boat itself is a 1993 Sea Ray but all numbers to the sterndrive and gimbal have faded away.

Then your original pitot tube fitting ought to be up top as described.

 

[Galvez83]

Yes the gimbal currently on the boat the pitot tubes comes out of the top. I will be closing off the hole. The only thing that i was able to find are brass and stainless 304 plugs. I read that 304 is not very saltwater friendly and neither is brass. Bronze is the way to go but all available are square heads that wont really fit in the area. Any thoughts on what to use for closing off the hole?