Leaking lower unit...

[_brad_]

Hello all,

Well, I am realizing I must have a water leak entering my lower unit on my 1977 70 HP Evinrude. I have changed the lower unit oil after every outing and each time it ends up milky.

What are the most probable places for a water leak to enter the lower unit? I'm looking to install a new water pump kit here soon so I know I have to drop the lower unit in order to do that...

How should I go about performing the water pump kit installation and sealing up this lower unit water leak?

Any thoughts?


Thanks
Brad

 

[Xcusme]

Re: Leaking lower unit...

Brad, before you get nuts replacing seals and tearing into the lower unit, try replacing the fill and vent screw washers (or o-rings as needed). This is the first place to look for water intrusion into the lower unit , and is the cheapest fix. Refill lube and run around lake for awhile. Check fluid for a milkshake. If you still have water, drop lower unit, drain fluid and pressurize the lower unit with air 8-10lbs. Submerge lower unit in a water tank, leaks should be obvious (drive shaft seal, prop shaft seal, gear shift rod seal) and those pesky fill and drain screw seals. If you have fill and vent screws that are threaded all the way to the screw head, use flat seals. If the shaft is not threaded to the screw head, use o-rings. Your dealer will have both....

 

[Whitefox]

Re: Leaking lower unit...

This is an old thread, but comes close to my problem. I have a 1977 Mercury 7.5 hp outboard. I had noticed that there was a bit of oil evident on the lower unit. I was going to change out the oil, and drained it,, that's when I knew I had trouble, the oil is clean, but there was not much of it. I removed the prop, and it appears that the prop shaft seal is leaking, as there was oil collected in the cavity that is behind the prop. The shaft turns smoothly, and I do not feel any play in the bearings. I would like to keep it that way.

I do not have a manual yet,, but I am wondering how much work is involved.

I am new here,, does it show??

 

[kenmyfam]

Re: Leaking lower unit...

This is an old thread, but comes close to my problem. I have a 1977 Mercury 7.5 hp outboard. I had noticed that there was a bit of oil evident on the lower unit. I was going to change out the oil, and drained it,, that's when I knew I had trouble, the oil is clean, but there was not much of it. I removed the prop, and it appears that the prop shaft seal is leaking, as there was oil collected in the cavity that is behind the prop. The shaft turns smoothly, and I do not feel any play in the bearings. I would like to keep it that way.

I do not have a manual yet,, but I am wondering how much work is involved.

I am new here,, does it show??

Whitefox,
Start your own thread on this. Give all the symptoms and observations. You will get a much better response. If the oil is clean and not looking like milk shake then nothing is getting in there. If what you are finding is black and smells of gas then it could just be unburnt 2 stroke oil.
Welcome to iboats

 

[Whitefox]

Re: Leaking lower unit...

ok thanks I will resubmit this.