Lost oil in sterndrive

joelger

Seaman
Joined
Jul 29, 2021
Messages
60
I recently had to replace the tube that runs from the sterndrive to fitting in the transom, along with the fitting itself. The fitting cracked and oil was leaking. Fortunately i was able to do this without removing the outdrive. I had a very small amount of water in the outdrive (cloudy oil) when i drained it. I filled it as per the service manual. I ran the boat for about 4-5 hours and found that i lost a few ounces of oil. The tank is well below the minimum mark and was full when i set out. I drained some oil and the oil is pretty clear. Perhaps a very small if any cloudiness.
Im wondering if the apparent loss might just be some air in the system that worked itself out while i was running the boat. As far as the slight if any cloudiness in the oil, could it possibly be some residual moisture from the first batch of oil i removed. Im inclined to believe that something remains in the outdrive after draining it.
I don't see any indication of oil leaking and if i lost that much oil i would think there would be a clear indication of water in the current oil.

Thoughts anyone?
JG
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,387
pressure testing is the only way to check for leaks. it requires you to drain the gearcase completely then pressure test.
 

Grub54891

Admiral
Joined
Jun 17, 2012
Messages
6,167
What Scott said^^. Also remember that it won’t pressure check properly with the drive installed on the boat, the pressure will simply go to the oil tank in the engine bay Unless you can seal off the tank or line going to it.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,130
I filled it as per the service manual. I ran the boat for about 4-5 hours and found that i lost a few ounces of oil. The tank is well below the minimum mark and was full when i set out.

Ayuh,.... That's quite normal,......
 

tank1949

Lieutenant Commander
Joined
Apr 4, 2013
Messages
1,911
Refill and remeasure. Any wet spots under OD where u park boat???
 

ROY WILLIAMS

Chief Petty Officer
Joined
Aug 8, 2022
Messages
427
use a air pressure 7-10psi in the outdrive . then the air is dropping spray a dish soap and see if the seals are bubbles up then fix the seals ... or a alum crack ..............
drain the gear oil then inspect the leaks ...
I flushed outdrive , used engine oil 0-20wt ...gear oil is dirty / water in it or steel particles ..on top of the flush port and drain the lower port.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Hi. Defo normal. Every time I change the gear oil each year..inlet it all drain out, including the header tank. Then when you put oil in the drive and then fill the tank above…there is always a void between the fill level on the drive and the tank. The oil takes a while to take up this void. Usually have to top up at least once or twice after an outing or two.
 
Top