Moly grease on U-Joints

[DrRoughneck]

It's a common recommendation to avoid Moly-enriched lithium grease on ball bearings because moly can cause galling.
Spicer U-joints contain bearings but they are not rotating entire revolutions like a wheel ball bearing. Rather bearings at the end of each "cross" of the U-joint rotate slightly when the angle change, if not at all.

Since these bearings act differently from wheel bearings, would a mildly moly-enriched lithium grease still cause galling? I'm thinking of the Synpower NGLI2 with 1% Moly.

 

[Ramblejam]

SynPower grease is perfectly acceptable for your u-joints.

Generally speaking, high % moly greases can be problematic in high-speed bearings ("skidding"). Neither of these are applicable to your situation.

 

[DrRoughneck]

Any possible downside to using this grease in U-Joints?

 

[buck91]

I don't believe I've actually used Synpower on u-joints since I always go with sealed units when I replace. That said, valvoline specifically advertises as suitable for u-joints on the packaging.

My thoughts are that I would be 100% OK with it given the fairly low (1%) moly. Depending on how frequently you are greasing them perhaps it would be a nice excuse to purchase a second grease gun and run whatever you feel like in there.

 

[Y_K]

In short: salesmen recommend it, failure analysis engineers recommend against it. You can find a few fascinating discussions right here, if you scroll a few years back.

Anyway, in this competition salesman always wins..

 

[DrRoughneck]

Originally Posted By: Y_K
In short: salesmen recommend it, failure analysis engineers recommend against it. You can find a few fascinating discussions right here, if you scroll a few years back.

Anyway, in this competition salesman always wins..

I've read of failure analysis on wheel bearings which rotate continuously but UJoint bearings are semi-static, hence my original question.

 

[Ramblejam]

Originally Posted By: DrRoughneck
Any possible downside to using this grease in U-Joints?

Are you trying to find the best grease, or just something that'll work?

 

[Chris142]

I have put over 100k on my u-joints with moly grease. No issues with mine. I replaced them to get away from the greasables and they looked great.

 

[Kestas]

I use Kluberplex BEM 34-132 for my u-joints. It's a calcium based Grade 1.5 grease designed for micromotion bearing application. It's resistant to high temperatures and rated for 2000 hours at elevated temperature. The calcium base gives excellent resistance to water washout.

 

[Y_K]

Where do you buy Kluber? Currently unavailable at Amazon and $65 at eBay - 4x of LE product

 

[Kestas]

Some time ago I saw it sold on line for motorcycles. I got mine from my colleague, who had hundreds of greases... free samples from suppliers for evaluation.

Edit: Wow! I just looked up prices for the grease. I never realized it was so expensive! Not that expensive when you consider how little you need for u-joints. I'm not sure you can buy it in small quantities.

 

[tdi-rick]

Originally Posted By: Y_K
In short: salesmen recommend it, failure analysis engineers recommend against it. You can find a few fascinating discussions right here, if you scroll a few years back.

Anyway, in this competition salesman always wins..

It depends on the platelet size of the MoS2.

eg. CAT greases with moly are claimed by CAT to be ok to use with rolling element bearings, and are what I use as a chassis grease for sliding splines, ball joints/tie rod ends and uni's, their 'Desert Gold' grease being my favoured flavour ATM.

 

[Y_K]

5% of Moly is great for HD sliders, no argument there. Why their outstanding ball bearing grease has no Moly then?

And how much is the Gold in AU?

 

[DrRoughneck]

Originally Posted By: tdi-rick
Originally Posted By: Y_K
In short: salesmen recommend it, failure analysis engineers recommend against it. You can find a few fascinating discussions right here, if you scroll a few years back.

Anyway, in this competition salesman always wins..

It depends on the platelet size of the MoS2.

eg. CAT greases with moly are claimed by CAT to be ok to use with rolling element bearings, and are what I use as a chassis grease for sliding splines, ball joints/tie rod ends and uni's, their 'Desert Gold' grease being my favoured flavour ATM.

Cat Desert Gold has 5% MSO2: https://parts.cat.com/wcs-static/pdfs/NEHP6012-02.pdf

Are U-joint bearings on a CAT much different from U-joints on a pickup, except for scale ?

 

[tdi-rick]

Originally Posted By: Y_K
5% of Moly is great for HD sliders, no argument there. Why their outstanding ball bearing grease has no Moly then?

And how much is the Gold in AU?


I don't use it in situations such as wheel bearings, use a HT bearing grease there, but haven't had an issue with the rollers in uni's, and as I said, CAT suggest it's fine in that application, according to the tubes I have.

This is out of an old ('09) catalogue;

"This grade has a median particle size of 3
microns in order to meet the special requirements of
some rolling element bearings"

As for $, I honestly can't remember.