As gun lube, any difference in automatic and manual transmission oil?

[MIL-DOT]

Over the years, I've read of a great many people using transmission fluid as a gun lube, but it seems that 100% of the time, they always specified 'automatic' transmission fluid, or abreviated it ATF.
I ask because I happen to have a couple quarts of Honda manual transmission oil buried in the garage, and I've long wondered if there was any difference, as it would apply to use as a gun lube.

 

[General Geoff]

Big difference. Traditionally, manual transmissions were lubricated with just heavy gear oil. Automatic Transmission Fluid (ATF) is closer to a light motor oil but with more detergents added. Many manual transmissions today call for (rather counterintuitively) ATF as lubricant.

 

[Jim Watson]

Seems to be about like 10W30 oil with more additives for the gears.
Ought to work fine.

 

[v35]

In addition to being a lubricant, ATF is a hydraulic fluid with detergent properties. It also is used for power transmission as well as to conduct heat away from the transmission.

Manual transmission fluid does not need to perform hydraulic functions, so it is generally more viscous than ATF. It can also withstand a lot of heat, and I'm not aware of any manual transmissions that have separate oil coolers.

Some manual transmissions can use ATF, but not the other way around.

The suitability of either one for firearms is another question for which I don't have an answer.

Source: I'm an engineer too

Also: Lately I have been using synthetic lubricants for certain guns. It won't evaporate as easily, and I believe it is more impervious to rust-inducing moisture. That's only a storage concern. Strictly in terms of lubrication I think you can use almost any lubricious substance for a gun (yes that's a real word ), as long as you clean and re-lubricate after shooting.

 

[HoosierQ]

Manual transmission oil used to be 90 weight gear oil. Thick as warm tar. It might work well enough. ATF is thin and very slippery. Used to be whale oil back when they invented the automatic transmission.

 

[MIL-DOT]

Big difference. Traditionally, manual transmissions were lubricated with just heavy gear oil. Automatic Transmission Fluid (ATF) is closer to a light motor oil but with more detergents added. Many manual transmissions today call for (rather counterintuitively) ATF as lubricant.

Thanks Geoff, that makes sense. I believe ATF is typically red in color, and is fairly thin. This manual stuff i have appears to be the same color as regular motor oil, and appears noticably more viscous than the thinner ATF.
(edit: and thanks to all others that posted since.)

 

[FireInCairo]

Some of the good qualities of ATF is it's long life and high tolerance for heat:

"Automatic Transmission Fluid is used in everything from a Fiat 500 to a Ford F-150, and because of the astounding service life required by vehicle transmissions, the fluid used is some of the most high-quality lubrication available. ATF experiences such extremes in temperature, humidity and viscosity, yet can last 30,000-60,000 miles or more."

http://www.mobilehydraulictips.com/5-things-father-never-told-mobile-hydraulic-fluids/

 

[mjsdwash]

Some cars use atf in the gearbox. Kias for example. Some hondas may as well. Either way heavy gear oil won't hurt. Atf is dyed red. Power steeriing fluid is nearly the same thing without the dye and may not smell as strong. Try it and see if you like it. I use 5w20 myself

 

[yugorpk]

Make no mistake about it. ATF is oil. Its just oil that has some more detergent , dye and its generally lighter vicosity. I used to build drag racing transmissions that Id run behind 1000 HP drag motors and I'd straight 0 weight motor oil as the transmission fluid. It shifts fast .

 

[H&R Glock]

I'm going to use that high detergent trans fluid to lubricate my guns too. Then I won't have to clean them

 

[cfullgraf]

ATF and gear oils have different additives for their specific application.

Many gear oils contain extreme pressure additives while ATF contains additives geared towards hydraulic needs of a automatic transmission.

Detergents are one additive to oils but by no means the only additive.

ATF used to contain whale oil but no longer for a variety of reasons not the least of which was a moratorium on the use of whale oil.

ATF is dyed to help distinguish it from other motor oils.

Many gear oils are very viscous at room temperature and have a distinct aroma that is unpleasant to me. I would probably not use them on my firearms for those reasons.

ATF (Devcon) is an ingredient of Ed's Red bore cleaner.

 

[Timtoolman]

Some. ATF is blue also B&M trick shift its a high Perf fluid with different lubricants . Should work well also and the lube would be blue to.

 

[ThomasT]

I think you need to use automatic transmission fluid on your autos and for manually operated guns like bolts, pumps and revolvers use manual transmission fluid.

 

[Elkins45]

ATF is more like what you would think of as a typical gun oil. It stands high heat very well. It also has very good penetrant qualities. A mix of ATF and acetone is said to be a better penetrant and parts breaker than even Kroil, PB or Liquid Wrench.

All my guns get lubed with a mix of two parts ATF, one part STP and one part Mobil 1 synthetic. I've been using this mix for 25 years now and I don't plan on changing anytime soon--I still haven't used up the quart bottle I mixed up all those years ago

 

[bluetopper]

All depends on what gear I want to run my gun in.

 

[DaisyCutter]

I use 50/50 ATF/kerosene mixture as solvent, and 5-30W motor oil as lube.

I just got tired of needing special gun oils, etc.

I have a couple dozen guns, and they all work fine this way.

 

[Tom488]

How come no one ever asks if they can run Hoppes in their cars?

 

[Deus Machina]

How come no one ever asks if they can run Hoppes in their cars?

Because it would need $300 worth of Hoppes.

I haven't had good luck with the Ed's Red formula. The ATF and acetone always refused to mix, or even emulsify. Maybe the cheap store-brand stuff or even Mercon vs. Dexron have different ingredients.

 

[ColtPythonElite]

I have had nothing but excellent results with Ed's Red

 

[YankeeFlyr]

Like v35 said...Manual gearbox oil is very simple (at least compared to modern ATF). Yes, gear oil of course has additives, and gear oil for front and rear differentials has historically had friction modifiers in it..like as specified/not-specified for limited-slip diffs.

(Some gear oils are rated as "hypoid gear oils" meaning it has extra capability for buffering stress concentrations on some gear mating geometries.)

Nevertheless, they are almost always thicker than any automatic tranny fluid in current service.

I've used ATF on slides and locking surfaces before, in a pinch, but never fooled with them enough to get a good feel as to their suitability for field temp ranges, longevity, suspension of grime, etc.

 

[TimSr]

I have to admit that I get kind of chuckle when people put a lot of thought into picking "the best" oil to lube a slide or trigger assembly that might be used 50 or a even a hundred times in an hour, and then wiped off and re-applied, or to simply coat the metal to prevent rust. The oil that was developed to lube a car for several thousand miles with moving parts moving thousands of times per minute, constantly, over hours at a time, exposed to burning fuel and chemical byproducts, and extreme heat is more than adequate to lube your slide or cylinder pin for a range session without having to get into whether the 3,000 mile automotive oil or the 15,000 automotive oil will best hold out for a 100 rounds of your slide moving. Whether you use tranny oil, gear oil, Mobile 1 synthetic, or Dollar General 10w30, your car will probably know the difference, but your gun won't. The only real consideration is if your lube will get thick enough to slow any moving parts in extreme cold, or does not repel water and moisture.

 

[stchman]

Big difference. Traditionally, manual transmissions were lubricated with just heavy gear oil. Automatic Transmission Fluid (ATF) is closer to a light motor oil but with more detergents added. Many manual transmissions today call for (rather counterintuitively) ATF as lubricant.

ATF actually has less detergents in it that motor oil. Automatic transmission aren't nearly as dirty as an engine.

Honda manual transmission fluid is very much like a 5W-30 motor oil so the OP should have no problem using it to lube his guns.

 

[MIL-DOT]

Wow, I never imagined this off-the-wall thread-topic would get so much mileage, LOL!!!
Anyway, thanks for all the solid replies,guys !

 

[Milkmaster]

Manual transmission oil used to be 90 weight gear oil.

I might mention that old type manual transmission 90w gear oil has quite a pungent odor that would not be pleasant to have around every time you handled your guns. I would choose something less odiferous!

 

[Drail]

Gear oil for gun lube? NOOOOOOOO!!!!!!!!!! Dexron? YESSSSS!!!!! Dexron is one of the finest oils we have today and it cuts carbon really well. And it's cheap and available almost everywhere. I've been using it on guns and shop tools for many years. Makes a great lock cylinder lube also. The only thing I have ever used 90W gear oil on was my motorcycle chains because it works better than anything else - but it almost makes you gag from the smell when you brush it on.