March 8th, 2010.
Jimm1009:
I know you are worried about your deuces engine, but consider how old the design was (and is), how much abuse and use it had before you got it, and how much better a lot of our lubricants are now compared to the 1940's and 1950's (much less then farther back, image what a Model T engine has had to take to survive?).The Lucas gear additive for transmissions is a heavy gear oil formulated to resist shearing as the gears rub togather. The engine oil additive is probably nothing more then a gear oil added to the usual 15W-40, which in that case, it would lubricate no less then straight 15W-40.
My M35A2 had a bad leaking rear main seal that got worse and worse, when you parked it it looked like a Model T had been there (Model"T"'s are notorious oil leakers, it's just the technology available at the time of the design), and the truck went from using a quart every 1000 miles to one every 250 in short order. After the main seal got replaced, the truck has not had the problem of big leaks, but it is a rare M35A2 that doesn't drip here or there occasionaly.
Before Edwin Drake's celebrated Oil Well at Titusville, Pa, (1857), machine operator's were at their wits ends as to how to handle increasing rotational speeds with tallow and animal/vegetable based lubricants. Without Drake, the Civil War might have well been fought with sticks and stones, as the machinery was taking horrendous abuse from lubrication failures. I have run 1830-1864 machine tools and overhead drive trains, they were designed for tallow (the bearings), and to get them to operate today takes 50/50 4o weight oil and 90 weight gear oil mixtures, to keep them from throwing the lubrication out of the bearings.
Your deuce has the same problem as most of ours without JATONKAS lube filter kits, in that after 6 hours of shut down time, almost all the oils in the sump (crankcase), and the cranks, crankshaft and camshafts are sitting on essentially dry bearings. Due to the time it takes to fill and pressurize all the galleries and bearings on start up, out truck engines suffer excessive wear to the bearings that could have been avoided in the original design by permiiting the pooling of some oil in the right places. The thicker anti leak additive to the Lucas oils allows some, like gear oils, to stick to the bearing surfaces and buy us some time by reducing wear on the rotational bearing surfaces. Over the long term these engines will suffer bearing failures prematurely due to this quirk of the original design, unless compensated for. The engines would probably go a million miles if we didn't shut them down every day or every few miles, but we do, and they pay for it.
A lot of fellows swear by the additives, others swear at the addittives, it's almost like family politics and religion, what your father taught you is law, and most of us quail at deviation from the Holy Writ. Marvel Mystery oil??? ATF! but it is good a breaking free frozen or stuck engine parts for rebuilding, and it helps keep my 1958 Ferguson MF65 Continental gas engine running on unleaded, as otherwise I get sticking valves. Some things, like some engines, make their own demands to survive. Just go with it and your deuce may go a few more miles before the inevitable overhaul.
Just a thought, Good luck with your quest for enlightenment,
Cheers,
Kyle F. McGrogan
I'm always amazed at some of the odd things that turn up on the internet. 
