Logo
FULL SITE MENU

Water in lower unit

G

gizmolvr

Contributing Member
"I have a 1978 140 johnson. Dr

"I have a 1978 140 johnson. Drained the lower unit and found the oil to be milky and discolored(no metal particles or anything like that). What seals should i be looking at? Was fine at the begining of the season but when i was draining to do the water pump found the water in the oil. I have changed props multiple times this year, could I have knocked a seal loose or something like that? Where should i start looking? Should i pressure test and how do you do it? thanks"
 
"I pretty sure that the seal y

"I pretty sure that the seal you have broken is on the drain plugs themselves. Check to see if you have a seal on the bottom one especially though because i'm not sure if the top one requires it or not. All though i think they do. Check that first, it the easiest and cheapest."
 
"I will check them out, pretty

"I will check them out, pretty sure the seals are there. There is nothing leaking out of them so i am sume nothing would get in. What else should i check"
 
"The sealing washers on the le

"The sealing washers on the level and drain plugs are one possibility. Water could get in without any noticeable leak of oil. The experts tell us that they should always be renewed when doing an oil change!
The other likely places are the prop-shaft seals, the drive-shaft seals and possibly the O ring seal on the shift rod.

A pressure and vacuum test will identify the location of the leak but the sensible course of action is to renew all the seals. Note that where seals are fitted in pairs they are fitted "back to back" so that one keeps the oil in while the other keeps the water out.

This diagram shows all the parts. #31 are the prop-shaft seals, #7 are the drive-shaft seals and #25 is the shift rod seal. Obviously you would have to renew any other gaskets or O rings you disturb."
 
Back
Top