TOPIC: Older Johnrude Gear Grease

I've been using 90W in my 56 Lark and my 58 18 horse as I couldn't find anything else that I was sure of. I want to find a grease that will stay in the gearcase and not let water displace it. I was told from a Mercury guy to use Moreys Red Grease which I can't find anywhere. What will work best?

Your best bet is to reseal the LU with new seals. SAE 80/90 is the correct lube (the original manual says "hypoid" oil) and grease will increase resistance hurt performance and fuel economy. It also depends on how bad it is leaking, does the oil turn milky immediately or does oil drip out of the LU? If there are no visible leaks and the oil turns milky over a period of a month or so simply change it often if you don't want to tackle the seals, however if the oil is dripping out change the seals. There really isn't another option that will work.

It's just a little late in the season to tackle it now on the 18 and it doesn't leak out. The Lark does and I have to pull that one apart. I remember everyone using something more of a thin grease when I was a kid, that's why I asked. Thanks for the help.

You may be thinking of the old direct drive outboards. Many, if not all, use grease. The invention of shifting began the use of 80/90 gear lube. Leaks and/or water intrusion mean bad seals that need replacing.

The bearings were designed to work properly ( for a long time ) with gear oil.--Replace the seals and use gear oil in it.----A lot easier and worry free if thing are repaired properly !