M35A2 gear lube/transmission

[WarCloud]

Who knows what type of off the shelf trans lube and how much goes in the M35A2 trans with no PTO? These damn manuals just refer me to a lube table that gives me a DoD inventory number that is useless.

What kind of trans lube does it like and how much? Anybody know?

BTW..trans fell off bellhousing because Gomer at the overhaul depot did not aircraft wire the bolts, so they simply unscrewed themselves.

I'd suggest anyone with a freshly won M35 series to crawl under there and remove the little inspection cover on the bellhousing and look at the big bolt head right inside. If there's no safety wire, you got troubles.

 

[DanMartin]

I did a bit of research on this..heregoes:

I used GL-5 (MT1) rated lube (yellow-metal safe) in everything on the truck. 5 gallon pails at Costco are about $45 or so.

Remember that the MT1 rating is critical if using GL-5...if not there, it will eat up the yellow metal components (synchros) in the tranny.

If you can still get it, GL-1 is the stuff that Uncle Sam used in these trucks for years, but the GL-4 or GL-5 (MT1) stuff is better for the differentials (technology gets better over time). The transmission does not *need* GL-5, but I'm lazy and only want to deal with one type of lube. Sometimes you'll see lube referred to as GL-4/5 MT1 as well.

So...to sum up: Stock is GL-1 for everything, GL-4 is better (replaces GL-1 is most applications), and GL-5 (MT1) is best for differentials, but safe to use for the whole truck as long as it has the MT1 rating.

Do a search here for GL-5 and you'll see some good posts here with links to external sites with more research and analysis information.

Hope that helps...

 

[WarCloud]

lube

HUGE help..thanks a ton!

 

[wsucougarx]

RE: lube

I thought it was GL-5 MT-1 rating was safe for yellow metals. Please correct me if I am wrong

 

[DanMartin]

RE: lube

Correct WScougarx. I fixed my post.

This is what I get for not being properly caffeinated when posting.

See, this site is self-correcting!

 

[66Reo6X6]

Good Info. Thanks

 

[Garandfan]

GL 1. 5 gallon bucket at Napa. without pto, about 4.5 qts, one knuckle.

 

[jeep454x4]

Had a quick question while on trans lube. I was under my truck an M35a2 and noticed that the bolts on the transfer case were weeping I wouldn't really call it a leak, I tried to tighten them but they are all ready tight as ****s hat band. Is it normal or should I pull the bolt one at a time and seal around them.

 

[jeep454x4]

Sorry meant to say that the trans is doing the same thing and that this truck was a depot rebuild with less than 1k on since the rebuild,but has a lot of stand by time. since about 98.

 

[paulfarber]

I don't want to start another holy war but using GL-1 in your driveline is not the best idea.

First, GL-1 as an official specification does not exist anymore.

Second, GL-5 is everything GL-1 is plus more goodies.

Third, your truck has had GL-5 in it since the early 1980's with absolutely no issues.

Fourth, there are no current lube orders that say to use GL-1 in a deuce. EVERY TM was changed in the mid 80's. People that are saying that GL-1 is the official/correct lube are out of date (and out of touch, IMHO).

Fifth, a lastly, GL-5 is all over the place (dare I say even WALMART carries it?). GL-1 is not.

Buy a big 5 gallon pail of GL-5 (technically you do not need the MT-1 spec... but it will not hurt if you do) and a 5 gallon pail pump from HF, Northern Tools or Tractor Supply and start filling (remember 1/2inch below the fill plug).

 

[KsM715]

People that are saying that GL-1 is the official/correct lube are out of date (and out of touch, IMHO).

Can you not post anything usefull without that roll attitude?

Whats wrong with saying "GL-5 is the modern day GL-1, it will work just the same and is much easier to find"

 

[PropDr]

I don't want to start another holy war

Really?

 

[m-35tom]

??? paul is absolutely right and is just giving helpful info to those who just don't know. at least he didn't say that you can use 30 or 40 wt motor oil in the trans and transfer, giving me the chance to say it. yes i have used it for 15 years. as far as lock wire, i don't know where anyone has seen that, i never have nor have i seen loose bolts although i completely believe it. (the loose bolts)

tom

 

[paulfarber]

Can you not post anything usefull without that roll attitude?

Whats wrong with saying "GL-5 is the modern day GL-1, it will work just the same and is much easier to find"

What attitude? Any suggestion that GL-1 is the proper lube defies all logic. It has been eradicated from all deuces since the early 80's. There is no written Army documentation that says to use GL-1 for over 25 years.

 

[KsM715]

Well then just say that without the (and out of touch IMHO) bs.

There's a right way and a wrong way to state your opinion, and you seem to choose the wong way everytime.

 

[jasonjc]

??? paul is absolutely right and is just giving helpful info to those who just don't know. at least he didn't say that you can use 30 or 40 wt motor oil in the trans and transfer, giving me the chance to say it. yes i have used it for 15 years. as far as lock wire, i don't know where anyone has seen that, i never have nor have i seen loose bolts although i completely believe it. (the loose bolts)

tom

Hey Tom
To save me from having to seach the 9,999 threads on this what 30-40 wt oil do you use? Anything I need to look for in the oil? I'm getting ready to put my trans back together and want to try the 30-40 wt oil this time around. Thanks

 

[stumps]

Fifth, a lastly, GL-5 is all over the place (dare I say even WALMART carries it?). GL-1 is not.

Buy a big 5 gallon pail of GL-5 (technically you do not need the MT-1 spec... but it will not hurt if you do) and a 5 gallon pail pump from HF, Northern Tools or Tractor Supply and start filling (remember 1/2inch below the fill plug).

The government's lube order is about logistics, not about what is best for your transmission. They clearly preferred to sacrifice some life, and shifting smoothness, for the efficiencies gained by stocking and transporting only a single type of gear oil. Just like they prefer to run everything off of JP5 jet fuel (rather than diesel and JP5 and ...) .... a decision that is more about what is best for logistics than what is best for the different types of vehicles.

Rockwell/Meritor says not to use multi-viscosity oils, and not to use oils containing EP additives in their transmission. They are very clear about it. They recommend ordinary SAE50 motor oil as the best lubricant for their gearbox. The old GL1 specification is also acceptable to them, but the multi-viscosity GL5 the government specified in their LO is not recommended. Rockwell/Meritor's literature for this transmission has been posted numerous times on this website.

On this website, we happen to have a number of members that are experts in this transmission. ... M-35tom is one. He is manufacturing a replacement overdrive gear set for this transmission to make it a bit more highway friendly. Tom recommends SAE30 or SAE40 motor oil as the best oil.

And, more than a few of us have discovered that replacing the GL5 that came with our deuces with the manufacturer's recommended SAE 50 motor oil improves the ease with which you can get the transmission into gear. The difference is like night and day.

What is best for us civilian owners of M35's is NOT necessarily what was best for the US Government when they owned these trucks! We gladly absorb all logistics costs of purchasing fuel and oils. The Government has a bigger stake in keeping those costs low.... Big enough to be able to weigh the cost of repairing transmissions against the cost of stocking and transporting two gear oils. Logistics won.

-Chuck

 

[Dipstick]

??? paul is absolutely right and is just giving helpful info to those who just don't know. at least he didn't say that you can use 30 or 40 wt motor oil in the trans and transfer, giving me the chance to say it. yes i have used it for 15 years. as far as lock wire, i don't know where anyone has seen that, i never have nor have i seen loose bolts although i completely believe it. (the loose bolts)

tom

Tom, I'm intrigued with the idea of replacing my transmission oil with SAE 50w motor oil. What brand of motor oil do you prefer? Are their any synchronizer/seal incompatibilities I should be aware of? My transmission sometimes won't go into gear after a stop. I leave it in neutral and let out the clutch a tad to spin the transmission and then it goes into gear. Thanks for your wisdom.

 

[m-35tom]

i use 40wt non detergent oil. as to not going into gear, 2nd especially, when stopped, that is completely normal and 40wt won't help. things just have to be moving slightly.

 

[welldigger]

i use 40wt non detergent oil. as to not going into gear, 2nd especially, when stopped, that is completely normal and 40wt won't help. things just have to be moving slightly.

Ditto. At toms suggestion I used 40wt non detergent motor oil in the tranny and transfer case. I can't say it was a night and day difference but it does seem to slip into gear a bit easier. Especially, at least in my case, first to reverse shifting goes a LOT smoother. Also that annoying first to second gap shifts a teensy bit better.