M35A2 gear lube/transmission

wanted to post a new thread do'nt seem able to anyway time for a service on my m35 what oils etc oh has winch i'm in europe so oil etc is sae numbers

hbear said:

wanted to post a new thread do'nt seem able to anyway time for a service on my m35 what oils etc oh has winch i'm in europe so oil etc is sae numbers

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LO9-2320-209-12-1.pdf
LO9-2320-209-12-1 Lubrication Order for the M35 series.

80/w90 GL-1 gear oil for axles, trans, transfer case, steering box, and winch. Make sure you change the oil in both sides of the winch.

40w non-detergent makes my trans shift more smoothly.

Easiest place to find was Tractor Supply for $22 in a 2 gallon jug.

http://www.tractorsupply.com/en/store/travellerreg;-non-detergent-sae40-2-gal?cm_vc=-10005

But for how long? How much have you ran it that way? These transmissions were barely heavy duty enough to stay in one piece in our trucks from the beginning, I certainly have some reservations about using an even lighter oil in an already stressed transmission. I'm sure it works fine for those of you who are running motor oil in the trans, but it certainly doesn't have the film strength that gear oil has, and doesn't stand shear loads without breakdown of the film strength either.

Why fight what the manufacturer recommends?

Because lubrication technology has vastly improved since 1949, and parts are getting more scarce for these by the day. The newer lube order calls for 80/90 anyway.

Jeepsinker said:

But for how long? How much have you ran it that way? These transmissions were barely heavy duty enough to stay in one piece in our trucks from the beginning, I certainly have some reservations about using an even lighter oil in an already stressed transmission. I'm sure it works fine for those of you who are running motor oil in the trans, but it certainly doesn't have the film strength that gear oil has, and doesn't stand shear loads without breakdown of the film strength either.

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You do realize that 40 wt motor oil and 80w-90 gear oil are almost the exact same viscosity right?

Jeepsinker said:

But for how long? How much have you ran it that way? These transmissions were barely heavy duty enough to stay in one piece in our trucks from the beginning, I certainly have some reservations about using an even lighter oil in an already stressed transmission. I'm sure it works fine for those of you who are running motor oil in the trans, but it certainly doesn't have the film strength that gear oil has, and doesn't stand shear loads without breakdown of the film strength either.

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The biggest issue causing transmission failure in the M35 appears to be due to lubrication not getting into the sleeve bearings on a couple of the idler gears. The hypoid gear lube's additives do nothing to improve that situation, and a lot to make it worse. It should be pretty clear from the ubiquitous use of 85W90 in the Army's LO's that the deuce's LO specified 85W90 in an attempt to make "one size fits all" specification. They were more interested in improving logistics of supply than they were in using the best possible lubricant for these old trucks.. The manufacturer of the gear boxes continued to recommend SAE50 all the way to the end of life for that gearbox. A few others have found that going down to SAE30 is even better. I like SAE40.

The difference between SAE40 and 85W90 isn't simply one of shifting feeling a little lighter, it is more that the synchronizers spin the gear clusters up more quickly, and stop blocking your entry into a gear.... you don't have to muscle them into gear like you do with the 85W90.

The nice thing about owning these trucks is you can go your own way.

-Chuck

i was told that my high speed whin could be inproved on my duece by swapping to 40wt non detergent oil.. im all ears with this discussion

PLease just answer the guys question with the facts.

Debate oils in your own threads.

I doubt they have TSC in the UK.

hbear said:

wanted to post a new thread do'nt seem able to anyway time for a service on my m35 what oils etc oh has winch i'm in europe so oil etc is sae numbers

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I see no reason why you can't post a new thread, your account is good.

welldigger said:

You do realize that 40 wt motor oil and 80w-90 gear oil are almost the exact same viscosity right?

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Yes I realize that, just as was stated before I could get back here, there is a vastly different additive package. Like was mentioned, run what you want. I just prefer the gear oil, and I run Lucas in mine on top of that, which may or may not be the only reason mine hasn't had any bearing or friction surface issues. I've been known to drive my truck for up around 20 hours straight with only short stops for fuel so I opt for the heavier lubrication.

My truck gets

multi-fuel fuel thru 3 micron (abs) filter
engine lube oil - Rotella T 15W40
transmission + transfer cases - non-detergent 40W
grease, everywhere it gets grease - GAA
differentials - Valvoline VV829
brakes - Dot 5
cornhead grease for the winch see video
These selections did solve some problems.

...........and the pictures for the General



cornhead
https://www.youtube.com/watch?v=UEwk_sYP6A8

as always thanks a lot it's good to know there are so many helpful folk out there have i got the only m35 in spain? got some strange looks when i took it to the supermarket a few days ago