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same information applies to every grease application on any kind
As for a marine grease, if it says lithium, it's gonna retain water
and wash out. Don't look at the name but the complex. I have several
M/C shops who use our 238 #2 and like it as they have pulled service
on bikes having this in there and found it to be the same as it
was when they put it in. One is a harley shop and another is a motocross,
For those that didn't see this I'm reposting the basics about grease
here for your convenience.
Grease is a complex of 4 items:
- Base complex
- Base oil
When looking at any grease all parts are equally important.
Unfortunately a lot of consumers are told by sales people that the
tac of a grease as the main component that makes grease better than
Some demos to show how tac holds up is by putting a dab of grease
on a surface, then smacking it with a hammer to show how the tac
hold's the grease in place (and hoping the grease being tested doesn't
splatter all over you). Another way, is to take a dab between your
fingers and pulling them apart. This too will show how much tac
is used. In that little test, you can actually count the amount
of "strings" or "fibers" that stay attached.
This too would prove the same basic point as smacking it with a
Tac is there to hold the grease in the bearing.
The complex also plays a role in a good grease.
There is many complex's available and used by grease manufactures.
2. Lithium 12-Hydroxysterate
3. Lithium Complex
5. Calcium 12-Hydroxysterate
7. Calcium Complex
9. Barium Complex
10. Aluminum Complex
Now the most popular complex that you will see used is the lithium
complex. Almost everyone has a tube of lithium in their shop.
So what does that do? It holds the base oil used as the lubrication
for the bearings. Oil cannot just be poured over a bearing as it
would simply run out of the bearing, therefore the complex holds
it in place until it is needed. As the complex heats up it allows
the oil to disperse and lubricate. As the complex cools back down
it is suppose to absorb the oil back into the complex. Here is where
it starts to get sticky.. This is called reversibility. This is
a measurement of how well the complex can take the oil back into
the complex. If the complex cannot take back in to oil, then the
oil will seep out and leave nothing but the complex and tac. Example
of this is when you pulled the cap off the front wheels of your
car or boat trailer and see the wax buildup in the little cap. So
this is a very important part of a grease as it is what maintains
the grease together.
More on the complex, Why so many different types?, There is certain
applications needing certain types. Extreme high temps like 900degs
would use a bentone (clay base) grease.
Here is one of the biggest problems that a grease has and many have
Ever see a grease turn milky looking? A lot of people have, especially
the ones sitting on the side of the road with wheel bearings wiped
The cause, water mixing with the complex. The most popular complex
(lithium) tends to do this more than some others. Lithium complex
is a soap base and will emulsify with water or retain water in the
complex thus the milky color. Of course water has what kind of effect
on metal parts? Another thing water does is thin out the complex
and then the oil will milk up and then the complex cannot retain
To see what I'm talking about try this.. Take a dab of grease in
the palm of one hand and put some water on it. Now with your index
finger, mix the water into the grease and see how it turns milky
and if enough water milks in, it will start to actually thin out
Consider that most equipment sitting outside, or expose to high
levels of cold and heat will be affected by moisture.
These are some of the reasons I will not use this complex myself.
Unfortunately most bearing manufactures tell you that lithium is
what they recommend and of course it is easier to obtain at just
about any parts house.
Now a lot of people think that if it is a synth grease as many are
nowadays, that it will perform better. Well, just like motor oils,
if extended drains are needed or extreme temps are met, then a synth
will be a good option but in most cases where grease is used, I
find, your application is more frequent due to the water washout
and such and that if the complex washes out so does your synth oil.
There fore, a lot of wasted money in that case. No, I'm not saying
that synth is worthless but with a high moisture application such
as a boat trailer or in cooling systems where high moisture is present,
using a lithium grease it is.
Ep additives is another part of a good grease. There is extreme
pressures present in all bearings as all the weight of your equipment
is riding on the bottom of that bearing thus it will squeeze out
the hydrodynamic properties of any oil thus relying on the barrier
additive properties of the grease. Most use a zddp or zinc type
of additive and then some of the more expensive use moly. Now again,
both work well, moly seems to provide a better barrier than zinc
under really extreme pressures as well as moly has a higher resistance
to heat. Again though, If your complex washes out, the barrier additive
does as well.
Are you starting to see where the complex can dictate a better grease
than just tac? I have seen some greases with dang near pure tac
and it looks like bubble gum. Problem though is when the complex
washes out taking the oil out, you have bubble gum in your bearings
with no lubrication.
The more tac needed, the less lubrication (or oil) is usually the
case, so depending on your bearing speed, determines the tac. the
higher speed bearings tend to use less tac whereas the slower ones
can have more.
If you want to avoid water wash out use an aluminum complex grease
with moly and it will not mix with water thus lasting longer and
you ultimately don't have to grease as much and end up using much
less over the period of a year and end up saving you money in the
long run. Also aluminum complex will mix with any other base complex
with exception to a bentone which wont mix with anything.
Well, that is grease 101."