Moly Grease In Wheel Bearings

[Bailes1992]

I'm looking to purchase some grease in the near future. I usually stock a lithium complex grease for general greasing and a moly grease for CV joints and sliding things.

However, I've noticed quite a lot of moly greases also being advertised for wheel bearings?

I was always led to believe that moly in a roller bearing, ball bearing, needle bearing etc is a bad idea as it can stop things moving/rolling and cause issues.

Is this still the case?

 

[Dave9]

Depends on amount of moly but yes, wheel bearings are better off with low (under 3%?) to no moly. If you also keep stock of a HQ non-moly grease, why consider this? On the other hand the most common consensus is if the manufacturer doesn't spec otherwise, use any NGLI# 2, GC-LB rated.

I'm sure there's bound to be a topic or two about this on BITOG.

 

[Bailes1992]

Depends on amount of moly but yes, wheel bearings are better off with low (5% max?) to no moly. If you also keep stock of a HQ non-moly grease, why consider this?

I'm sure there's bound to be a topic or two about this on BITOG.

Not something I'm considering. I just found it curious that some moly greases were being advertised for CV joints and wheel bearings.

Did have a search but didn't come up with a lot.

 

[Dave9]

Good/better/best situation? If one were best at everything, there wouldn't be all the others.

 

[Escape08]

I've used Valvoline DuraBlend Synthetic in the front wheel bearings of my 1984 pickup truck and never had a wheel bearing failure ever since. Just, pack the bearings with all the grease it can take and the base of the hub where the bearing is attached as well.. Never be stingy on grease when it comes to wheel bearings.

 

[kevperro]

The reason I've read is that a moly layer slows heat dissipation in the bearings. When you have something like a bearing that is spinning at relatively high RPM for hours at a time that can become an issue. Obviously, it isn't always an issue otherwise people wouldn't get away with running it.

I figure for the $6 a tube of grease cost me I'll go without the moly in the wheel bearings. Applications that call for it are where you have high shear forces like you see in heavy equipment. A tractor-trailer fifth wheel would be an application or a plethora of other big machines with metal-on-metal contact with high applied forces to the interface.

 

[Chris142]

Every 80's ford truck ( possibly longer) got 3% from the factory and the bearing lived normal lifetimes.

 

[kevperro]

Every 80's ford truck ( possibly longer) got 3% from the factory and the bearing lived normal lifetimes.

I think the magic number is <4% but I'm dubious it provides any benefit in a wheel bearing and higher levels can certainly cause harm. It fits in the "no reason to use in this application" territory.

I'm open to being proven otherwise.

 

[sk_pete]

I was always led to believe that moly in a roller bearing, ball bearing, needle bearing etc is a bad idea as it can stop things moving/rolling and cause issues.

Is this still the case?

me too.
i´d rather look for common ep grease

 

[Foxtrot08]

Depends on the percentage of moly and what sort of moly additive is used.

In general you don’t need it. But wheel bearings grease is often times used for other things than wheel bearings.


So.. yeah.

 

[Auto tech]

Wheel bearings in passenger trucks don't spin fast enough for a moly grease to harm them. We use moly formulated wheel bearing grease in our shop of fleet vehicles. Haven't had a bearing failure for 10 plus years

 

[Snagglefoot]

Some manufactures only advocate moly in heavy equipment such as Cats.

 

[JHZR2]

Some manufactures only advocate moly in heavy equipment such as Cats.

But that’s because of sliding surfaces. The point about no moly in bearings is because you want them to roll, not slide on a moly film.

 

[FCD]

Every 80's ford truck ( possibly longer) got 3% from the factory and the bearing lived normal lifetimes.

In the service manuals for both my Fords it says to use "High Quality Lithium grease" for the wheel bearings.

 

[sk_pete]

use "High Quality Lithium grease"

what a nebulous term... does that mean ep?
or should we grab crystal ball and read their mind?

 

[Rob_Roy]

If the grease is approved for wheel bearing use (GC-LB) and meets the temperature requirements for your application, I see no issue using a grease that contains moly. As noted by others, for many years ford spec'd a wheel bearing grease containing 3% moly.

If in doubt - consult your service manual and see what is recommended.

 

[nbpt100]

I have seen moly grease specified in bevel gear boxes used on Toro lawn equipment.