For all who have had the pleasure of working on modern steam: I've been asked if i can recommend a hard grease suitable for lubing the roller bearings on the big ends of a Garratt. I'm not sure if we in the US used hard grease in our roller bearing rods or not.....and, if so, what specific product might be available that would be appropriate for the purpose. Anybody know?

dave

I have to admit to being very disapointed. When I saw this thread appear, I was hoping for a lively discussion about hard grease (which I sorely need an education on) or at very least a discussion about roller bearings in side rods.....

So I'll ask my questions. What is available for in the form of hard grease for rods?

Who uses what?

How do you like it?

How are those who are exprimenting with oil in side rods doing? Has it proven to be worth the trouble?

There are hard greases for rods, but they're not used in roller bearings.

NZ spec is to use AAR M-942 roller-bearing grease in roller rod bearings (specifically citing M-942-75, which I believe is the first version of that standard). In some discussions I saw, there was a groundswell of enthusiasm for the Shell Alvania product. Part of the 'secret' in the M-942-spec grease composition is to use a base oil with higher viscosity, NOT a 'thicker' or 'harder' grease.

There are the usual caveats about ensuring enough expansion space, not overfilling the bearings past about 1/3 full, using a lithium or lithium-calcium base for moisture tolerance, right mix of EP constituents, corrosion protection, etc. Probably advisable to work up a good tight set of side seals for the bearings.

There is a point at which grease lube of rod bearings becomes less advisable than oil lubrication, but that's a pretty high rotational speed. I would expect 'wisdom' on this to follow similarly loaded practice, under comparable conditions, in the general machine industry.

I, too, am surprised that the tribology experts didn't chime in on this significant issue. (Perhaps now they will...)

Dave- Odds are very good these are SKF roller bearings (seems like they were used on most locomotives outside the U.S.). I'd think you'd have a good chance getting info on recommended grease from SAR records or someone familiar with their locomotives. The Class 25 4-8-4's had complete roller bearing rods; the GMAM and maybe another couple of classes of Garratts had roller bearing big ends on the main rods.

SKF themselves may be able to provide a recommendation. At any rate, I'll bet the info Robert provided above is good and is probably the same grease the SAR used.

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I think Ben isn't thinking about roller bearings in the context of his inquiry, just wanting to know about a source for good hard grease for a traditional split brass big end. Please somebody who knows where to buy the right stuff let us know. He's running short of his NOS supply.

I'm still waiting for more information about the hard greased Garratt big ends. If that was standard practice on some specific railroad, it is markedly unlike that used by every other one I've been able to find out about.

dave

Don't have time for a detailed reply or fact-checking, but wasn't there a thread on here fairly recently that talked about a foreign source for 'good' replacement Hymek 8?

I will look in my records this evening, lord willing, and see if I can find the reference.

RME

Here are some links for hard grease suppliers from the "steam locomotive repair/supplies links" section of my webpage (http://www.trainweb.org/tusp/r_links.html)

http://www.centurionlubes.com/sodabg.htm

http://www.steamservicesofamerica.com/

Diversified Rail Services (no website- Phone 715-294-4003)

Don't have time for a detailed reply or fact-checking, but wasn't there a thread on here fairly recently that talked about a foreign source for 'good' replacement Hymek 8?

I will look in my records this evening, lord willing, and see if I can find the reference.

RME