What grease should I buy for a grease gun?

Nov 11, 2020
Ontario, Canada
I would appreciate a very down to earth, practical recommendation for what grease I should buy to load into my grease gun that will probably live in that gun for the next 10 years and be squeezed into anything with a zirc fitting that I have when I think it needs it.

I know there's tons of stuff written about grease but at the end of the day when I'm staring at a retail shelf of grease tubes I'm probably not going to be able to put theory into practice based on what I see on the product labels.

Just to throw some words out -

High pressure, high temperature, lithium, cerulean, etc. What do I want?

What has zirc fittings? Various chassis joints. Then I have some wheel bearings (pillow-block bearings on a furnace fan). U-joints on a car drive shaft. Do they all need their own type of grease? I don't know. No clue.

I had a grease gun, can't find it, it took the large tubes (12 oz? 14 oz?), required 2 hands to use, was an absolute nightmare to load a tube in and screw the spring-loaded end cap on.

I recently bought a gun for the smaller tubes (3 oz I think). Trigger pump, needs only 1 hand to hold and squeeze. It has solid and flexible injection line that I can change to suit.

I've had a look around, I don't think it's going to be easy to find a store with a good selection of grease in the small tubes. So that could be a problem. Beyond that - what am I looking for?

I have 2 tubes on my garage shelf:

Mystic Hi-Temp multi-purpose grease (it's red). It has "far more protection than most greases". Protection? From what? Do I want protection, or do I want lubrication? I don't see the magic word "lithium" anywhere on the label.

The other tube - Unival, general purpose Hi-temp grease for wheel bearings and chasis. This is a Home Hardware store brand. It's dark green. Smell is similar to the Mystic. No lithium either.

I have 1 car ('67 Dodge) with wheel bearings that I might have to grease with my bare hands, but otherwise none of my other vehicles have grease-able wheel bearings. Wheel bearings might get hot, but I wouldn't think chassis joints (ball joints, tie-rod ends) would get hot. So does "Hi-temp" grease mean anything to me?

And what about lithium? What sort of mechanical object with a zirc fitting most definately requires a grease with lithium?

So what exactly is the deal with grease?
Unfortunately, I don't think it's that easy, the way it's been explained to me. There's no "use it for everything" grease. This is because different OEMs choose different greases for different applications. And different greases can have different bases. The soaps/thickeners in the base(s) can react with each other if mixed improperly. While it may be not big of big concern in the short term, in the long term the soaps can react badly/differently and the lube can fall out of suspension; obviously not a desirable condition.

Because of your goal (to have a grease in the gun "for the next 10 years"), you probalby cannot find a do-it-all grease.

You're going to have a pick a grease which is meant for your particular application(s). That may mean having more than one grease tube. Or if you want, have more than one grease gun for each dedicated type grease.

If you need a "GC-LB" or "NLGI-2", that's only a starting point. You'll want to know what base is used in the application, so that it matches what's already in the bearing/u-joint/bushing. It may take some research on your part. Those classes of grease can still have different soap bases, so just matching part of the equation still leaves an unsolved portion out there for a potential problem. For example, polyurea isn't compatible with much of anything but itself, whereas litium is compatible with several others, but still not all others. And, for another confusing example, you just cannot say "I need lithium"; there are not one, but THREE types of "lithium" bases (stearate; 12 hydroxy; complex) ... Polyurea is another example; there's conventional, modified, shear-stable, and LM types. The conventional type isn't compatible with anything else, whereas the shear-stable type is compatible with most other greases. So if you're getting a polyurea grease, you MUST CONFIRM what type you are getting to know if it's cross-compatible or not! FOUR polyurea types of grease for goodness sake!

Here is part of the problem I'm trying to show you ... say you want a Deere grease for "GC-LB" application(s) ...
BOTH of these are "GC-LB" and also "NLGI-2" rated, yet these have different soap bases.
Knowing just the service factor of the grease is NOT enough. You need to know what grease soap/thickener bases are present or you're going to end up with a problem! GC-LB and NLGI-2 are "service factors"; they tell you absolutely nothing about the type of soap/thickener used in the grease.
This one below is GC-LB, but not NLGI-2, and at least they tell you which greases this is compatible with ...
But notice that is does NOT say it's compatible with polyurea grease ...

This really is no different than saying you need a different lube for any other application. It's not a good idea to put GL-5 gear oil in your engine, and it's not a good idea to put tranny fluid in you differential. Unfortunately, OEMs are often not helpful in this regard, as they will give you a service factor to use, but they won't tell you what base soaps are present. Occasionally, the OEM is good enough to say what brand/product they used at the factory, but not often enough IMO.

All hope is not lost!
For some of these applications, what you may be able to do is "flush" the old grease out with multiple complete cycles of the purging/filling the cavity with a new grease. For example, with a u-joint zerk, you would not only just pump it until the grease "pops/cracks" (indicating it's receiving grease), but you'll want to pump copious amounts of grease through the joint and keep wiping away the old grease as it comes out. Then run that u-joint for a short period of time, and repeat the purge process several times. At least this way, the potential for incompatible grease reaction is reduced, if not eliminated.

I'm not a chemist, so I cannot vouch for the credibility of this info. But here's a chart and article which illuminates my point:

I get it; you want a simple answer.
Unfortunately, there isn't one.
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For automotive chassis and RV trailer wheel bearings and suspension parts I use an NLGI 2 EP high temp lithium grease (Red N tacky by Lucas or Mystik red tube)
When I was working we had a keg of similarly graded grease that we used on all aspects of our vehicles chassis, springs, brake actuators, pumps, lift cylinder joints and on and on.
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Some people should not own a grease gun. :D:D

I would think there are numerous greases for your gun that would keep your joints in good order. Older car forum for that 67 Dodge would probably be a good source of what grease to use.
Only Valvoline Crimson in my grease gun for 25+ years. The greasable deck bearings in my John Deere mower are the same ones installed at the factory in 1998.
I’m aligned with others that say Lucas red n tacky or Mystik red should cover most of your applications. I’ve been using either of these for several years now.

Just my $.02
Putting aside the issue of injecting a grease that's compatible or not with what's already in there ...

Is there a rule of thumb when it comes to where to use, or not use, a moly grease vs lithium vs something that is neither?

Is cold temperature (say, 10 to 40 f) on a suspension joint under a car more demanding than looking for a "high-temp" grease? Or is it that a high-temp grease is automatically good for low temps, freezing temps?

Should wheel bearings get a different grease than suspension / steering joints? What about U-joints?

And does the color tell us anything about the grease? Red vs tan vs green/blue?
Putting aside the issue of injecting a grease that's compatible or not with what's already in there ...

Is there a rule of thumb when it comes to where to use, or not use, a moly grease vs lithium vs something that is neither?

Is cold temperature (say, 10 to 40 f) on a suspension joint under a car more demanding than looking for a "high-temp" grease? Or is it that a high-temp grease is automatically good for low temps, freezing temps?

Should wheel bearings get a different grease than suspension / steering joints? What about U-joints?

And does the color tell us anything about the grease? Red vs tan vs green/blue?
FWIW I use the Lucas red n tacky or Mystik red in my RV wheel bearings yearly, my Ram u-joints during oil changes, my Jeep ball joints/tie rods during oil changes and my John Deere steering knuckles on my riding mower about once a month. All are different applications that get fresh grease as noted above. I’ve not had any issues yet.

Just my $0.02
I have a Dana Spicer U-Joint on my Isuzu pickup truck for more than 15 years and greased it with Mystik Red before installation. The sad thing is, I have a difficulty in re-greasing the U-joint every year because the grease fitting is hidden even though I used a needle grease adapter. So I said to myself, let that U-joint break and I will replaced it with a sealed non-greaseable U-joint. Well, to this day, it really amazes me Mystik Grease held up for more than 15 years. I just avoided going to flooded streets on rainy days.
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Below is a hodge-podge of things I found and / or re-edited or re-composed regarding grease as it relates to moly and lithium.

I believe that the only conclusion I can make from this is that:

a) don't use a moly grease on parts subjected to water ingress (which to me would be anything under a car, such as suspension and steering joints, u-joints and non-sealed wheel bearings that are manually greased when installed).

b) the use of "marine" grease (ie grease for wheel bearings for boat trailers) should be considered for general under-car lubrication I would think.

c) if greases are made up of soaps, oils and additives, a choice between moly and lithium is not really a true choice (or as a way to identify the grease type) as lithium is a component of the soap while moly is an additive.

d) moly should not be applied to surfaces or bearings subjected to a high rate of movement or rpm. But just what constitutes "high rate" is unclear. Many claim that wheel bearings, u-joints are not high-rate in this context.


Grease is made up three parts. First is the base (almost always a soap) that holds the second part, an oil, and makes it a solid. Third are various additives to change the behavior of the other components, provide protection if the grease is forced out of the contact surface, and to change the stickiness of the grease.

Lithium is used for the soaps of many general purpose greases. (calcium is used in cheap greases. sodium and barium based greases are also common, as are mixtures). 12-hydroxy-lithium-stearate That's just the "soap" component

Molybdenum dioxide is an additive, used for protection of parts when they're loaded heavily. Molybdenum disulfide that's the high pressure additive in "Moly" greases.

So there's no reason you can't have a lithium based grease with molybdenum, and, in fact, they're very common.

NLGI numbers refer to the hardness of the grease at room temperatue. No 2 is the most common grease grade.

concern about water resistance than anything else.

most manufacturers also add synthetic oil to the mixture, which accounts for the brown colour and nasty odour.

Resistance to water wash-out is a concern to bike owners. Grease for marine applications (boat trailer wheel bearing grease) is a favorite type for these people.

Castrol Pyroplex-blue. Very water resistant. It has metal additives that are activated by water, so it actually resists washout better when water gets into the bearing. Its spec'd for wheel bearing use. Very sticky, too.

Another great grease is Mystic GT-6 (low temp) in the green tube. Also pretty water resistant.

Moly fortified lithium grease is intended for extreame pressure conditions but are not particularly water resistant, which I think is the most important property for bike bearings.

Moly's water resistance is somewhat confusing. Some claim it is high, others say low.

Moly grease is also known as Molybdenum Disulfide. The grease is best applied to situations where metals slide over each other under very high pressure.

Conflicting arguments as to what constitutes high-rate metal-on-metal movement. Some say you need to be at many thousand RPM to be high-rate, and that wheel bearings, U-joints are not.

Moly grease is applied to metal components like spline, CV joints, universal joints, and gears. One good thing about moly grease is that its stability is not affected by dilute acid and oxygen.

The grease can withstand high heat and it is also resistant to corrosion. It has high adhesive properties, and that’s why it will stay in place for a long time.

When Should You Not Use Moly Grease?

Moly grease’s water resistance level is low. So, it is not applicable for areas where it will be exposed to excessive water ingress. Also, it is not advisable to apply grease to components that move at a very fast rate.

Lithium grease offers a higher level of water resistance than moly grease. Hence, moly grease cannot help much to ward off water ingress. Lithium grease does a lot better.
Color is indicative of nothing in a grease. I would stick with Lithium based on automotive applications. Its widely available and will be appropriate for your uses. If you buy a high temp EP grease it will be suitable for disc or drum brake bearings on older cars, pickups and most trailers. Dexter recommends this type of grease for their trailer axles and GM used to use it on their old style non sealed bearings and chassis
"Moly grease" is a grease--built with any type of thickener, including lithium soap--with molybdenum disulfide powder added to it. Molybdenum disulfide is good at reducing sliding friction, and the particles are very strong. On the flipside, the particles are relatively big in comparison to most machining finishes, including roller and ball bearings. Roller/ball bearings don't have sliding surfaces, so the moly disulfide doesn't assist these bearings well in general. Also, because the Moly disulfide is very strong, it has a tendency to press onto the asperities of these bearing surfaces, giving them a frosted appearance when taken out of service. This behavior is regarded back and forth between certain OEMs as either ideal or not, but when it comes down to it, either a grease passes GC-LB for anti-wear and EP performance in a ball/roller bearing or it doesn't. If I were you, I wouldn't buy a Moly grease as a do-all.
I had several containers of grease in my garage and was wondering if they were compatible.
I wanted to use one grease for maintaining my riding mower, push mower and snow thrower.

I believe using Lucas Red-N-Tacky will serve my needs.
One grease gun, one grease.

What would require a different grease?
* wheel bearings
* brakes