Lower Unit Lubricant

BuilderFL

BuilderFL

Junior Member
1980 200HP Merc. Black Max.

The lubricant is creamy in color, which I think is an indication of water seepage. Reading the repair manual, trouble shooting the problem is beyond my skills. Although the rest of the motor has been rebuilt, the lower unit is original and the only work done to it has been the replacement of the water pump and/or impeller various times, oil changes (lubricant) and replacement of the vent screw and seal washer. Is this something I need to address or not a big deal and just replace the lubricant monthly? Any suggestions on the repair? As always, your expertise is welcome and greatly appreciated. Thanks! ???
 
Creamy color is water! You need to fix asap!

Now you say that the lower unit oil has been changed, when was the last time? Did you or they replace the washers on the fill & drain screws when you did it?

I would drain all oil, replace screw washers, and refill.

If you get more water then you have a seal gone and it will need further work.

They can persure test the unit to see were it is leaking, but that might be best left to a pro?

Start with the screw washers and oil change.

Good Luck
 
Only replaced the vent screw and washer - will go ahead and replace the fill screw and washer. Thanks.
 
You will need to drain the oil and change the washers on both!!
This should be done everytime and on both!!

Good Luck!
 
The past 2 units I've changed the fluid in looked milky, both ended up being the seals under the water pump. Many people don't change out the water pump base, which leads to water intrusion down the road.
 
milky coloured oil can also be directly associated with excessive beer consumption while wrenching on your boat and is a warning sign that you might need the 12 step program to recovery :-[ ;D ;D
 
THEFERMANATOR, That's a god one - never changed the water pump base or the seal.

Hangbelly, Don't tell me that .... I just finished with step 12 last month, my fourth time. ;D
 
Hi Builder,

There is a product called "Seallube" which when added to LU oil swells the seals stopping the water intrusion into the LU. If the seals are really bad, Seallube may not work, but it's worth a try. Also, full synthetic lower unit oil can take alot more water than standard 90 hypoid LU oil before breaking down. My Yamaha 150 LU takes about 1.5 quarts of oil and I add 2 oz of Seal Lube to it when I change it. I bought the Seallube on Ebay. One of the V20 gurus (I forget which one) swears by Seallube. !

Geek
 
BuilderFl:

I have a lower unit pressure tester I can ship to you to aid in trouble shooting (as long as you send it back when your done - No Hammer I'm not giving it away :-).

t is often easier to ID where the leak is after pressuring the case. Let me know if your interested.

Kamikaze
 
Geekie1 said:
Hi Builder,

There is a product called "Seallube" which when added to LU oil swells the seals stopping the water intrusion into the LU.  If the seals are really bad, Seallube may not work, but it's worth a try.  Also, full synthetic lower unit oil can take alot more water than standard 90 hypoid LU oil before breaking down.  My Yamaha 150 LU takes about 1.5 quarts of oil and I add 2 oz of Seal Lube to it when I change it.  I bought the Seallube on Ebay.  One of the V20 gurus (I forget which one) swears by Seallube.  !

Geek
Click to expand...

That Seal Lube is the stuff use it on every lower unit change and in my oil changes on my cars never have a leak in anything i ever used it in.
 
Builder, just pull it down, put a water pump base in it( not that hard), put a shift shaft bushing( not that hard but does require a special tool), and then the only thing left is the prop shaft seals and you'll basically have a resealed lower. Prop shaft seals can be replaced with out pulling the shaft, its a little tricky. I think Ferm hit the nail on the head with the waterpump base being the problem, might as well put an impeller in it if you haven't done it recently
 
Thanks a lot guys,

I'm going to start with the easy repair first: Replace the fill and drain screws and washers and add Seallube and synthetic lower unit oil. Give it a month and it that does not do the trick, replace the water pump. Ultimately, I will take up Kami's offer on borrowing the lower unit pressure tester.

By the way, Hammer---the operative word is "to borrow" like in "To receive (something) from somebody temporarily, expecting to return it."

Reel, it still looks like sh_t. I screw in place a piece of old plexiglass, made one center hole and put a fuel gauge. I'm still trying to figure out besides the alarm, how I'm going to go about protecting my electronics. I will use my V20 until the "Florida Winter" and then dry dock and do the repairs. For now, as long as I'm back in the water, I'm happy. Thanks for asking. 8)
 
BUILDER:

THERE IS NOT EASY WAY OUT WHEN IT COMES TO LOWER UNITS, THEY ARE EXPENSIVE TO REPLACE. TAKE IT TO A REPAIR SHOP AND HAVE IT RESEALED AND PREASURE TESTED. (THAT'S A 1980 UNIT, 27 YEARS OLD!!!)

IF I CAN HELP CALL ME 888-1006 (YOU KNOW AREA CODE)

LESTERUS
 
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