What is thread size of bolt on Mercury 75 HP 1993

udoittwo

Seaman
Joined
Jan 23, 2014
Messages
73
I am switching from a 4 cyl.1986 75 Mariner to a 1993 Mercury. It has been setting for a few years so I am trying to change the water pump. The 4 nuts came off easily but the one brass lock nut that is up inside fell apart. Because the nut was spread apart, I thought it was a standard 3/8 16 but a 3/8 16 doesn't fit.Is it metric?
Thanks for your time and any answers,
Karl.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
8,776
Hi there, can you identify the nut you need using one of these parts diagrams?
http://www.mercruiserparts.com/Show...bnbr=200&bdesc=GEAR+HOUSING+(PROPELLER+SHAFT)

http://www.mercruiserparts.com/Show...277&bnbr=190&bdesc=GEAR+HOUSING+(DRIVE+SHAFT)

The 4 nuts that came off, are they the same size as the ones you need by chance? < For example, Item number 74 Merc part number 11-34933 in the first link looks to be 7/16 X 20, http://www.iboats.com/Mallory-Nut-S...9786989--session_id.093058620--view_id.364187

http://www.mercruiserparts.com/selectModels3.asp?type_id=MERC
 
Top