Looking at a US forum post earlier, there was some discussion about using John Deere Corn Head Grease for non-shift or early shifting gearboxes, or Lubriplate 105. I've used 105 for my 300s and the 400, all are pre 62 motors (without thru-hub exhaust). Having previously imported it from the US many years ago I am now running out. From what I can glean from the spec sheets is that 105 is multipurpose now, either branded as an motor assembly grease, or as a gear grease. I can't see anything to counter this - can anyone confirm?

http://www.ebay.co.uk/itm/LUBRIPLATE-NO ... Sw9mFWLhRI

https://web.archive.org/web/20120720152 ... _C-105.pdf

As an aside, many use conventional modern outboard gear oils where the seals in these early motors permit and as most of us with only run our motors for a few hours a yearm this can be an option, i.e. any water ingress is likely to be noticed...

Although a different design to the through hub exhaust lowers I can't see they can be fundamentally different from a construction point of view & would be tempted to use later type gear oil in place of the Lubriplate, a quick check after use will tell if it is getting contaminated. That's always assuming the seals will retain it of course.

Myself I use semi synthetic gear oil as commonly used in rear wheel drive (& some front) hypoid differentials on cars. I figure the loading in a hypoid diff is far greater than our outboards & have had no issues to date. I change it annually & it comes out clean. I believe 'proper' lower unit oil has different emulsifiers in it in case of water ingress, but it certainly smells the same as diff oil - i.e. of cat pee! I have plenty of it here at work & it is a fraction of the price.

Alacrity wrote:Myself I use semi synthetic gear oil as commonly used in rear wheel drive (& some front) hypoid differentials on cars. I figure the loading in a hypoid diff is far greater than our outboards & have had no issues to date. I change it annually & it comes out clean. I believe 'proper' lower unit oil has different emulsifiers in it in case of water ingress, but it certainly smells the same as diff oil - i.e. of cat pee! I have plenty of it here at work & it is a fraction of the price.

What grade are you using?

75/90 semi synthetic. The ToP on the Stapely seems OK with it.

Thanks. Less than half the price of Quicksilver on fleabay.

Have to agree with Alacrity, as far as I can see from the latest Lubriplate PDS - it's very low tech stuff, just mineral base stock blended with zinc oxide for water resistance, NGLI is 0 (brown mustard thickness) but absolutely no load bearing qualities listed (may not even have been tested, not even a 4 ball weld - standard industry test).
I think even modern water resistance greases would be better the old low tech stuff , but they tend to be a bit thicker with an NGLI of 2-3 (peanut butter) - but have much better load bearing qualities.

I have used fully formulated 75/90 synthetic gear oil from Exxon (a branded marine product, but can assure you that it was a re-branded automotive axle/gearbox product with API GL5 properties) in the gearboxes of our offshore racing Yamaha Pro-V 200's (2.7l) changed once per season (of up to 14 x 200 mile races) - never had a lower unit failure in 10 years, and with the lower viscosity we even gained a few rpm!

This may explain:- http://www.widman.biz/uploads/Transaxle_oil.pdf

Interesting reading..

I'd be happy running 75w90 in the post 62 Mercs. On the earlier motors, wouldn't really want to drain / heat the 105, so it flows out better, and then mix the two, but guess after a run one can drain the mix and refill.