Bill Howard, 2003 question:
An earlier post that pointed out the NEED to do the greasing, and identified the Lincoln Needle, also mentioned ‘Lubriplate’ as the correct grease! I talked everything over with my AI/A&E about the greasing – he is all for it, but he had no specific info about the actual grease. He is still waiting for delivery of the service manual he ordered for my plane…So – no spec.
Now I have the gun and the needle – BUT…I have been to all the stores – no Lubriplate in grease gun cartridges. The Lubriplate web site: www.lubriplate.com has virtually DOZENS of grease product!
It doesn’t seem that we need a ‘high-temp’ grease, more likely a water-resistant type that stays put and doesn’t run all over the tires or the bottom of the plane. Maybe one of those white greases for marine use?
(Search strings: best grease, right grease, Aeroshell, lubrication)
Editor’s 2003 response:
I’m surrendering to the temptation to throw in my input, to the past thread on greases. I’m not a big fan of varying from manufacturers’ recommendations in most respects. But I have to tell you, I have been thoroughly disillusioned by the recommended standard MIL-Spec Aeroshell #5 and #7 greases, and to a somewhat lesser extent, by the #22. My judgment is still out on the #22, but I’ll be able to decide by next May. I consider the #5 and #7 to be the worst of the lot for our casual (low-volume) use. If the aircraft is going through 100 hour lubrications (not just Annuals), and is flying hundreds of hours per year in commercial or training service; AND if the shop doing the greasing has high turnover on grease; then the #5 and #7 is probably OK. Under those circumstances, the grease in both the joints and in the guns is getting a rapid turnover. In private aircraft usage, the beef I have with these greases is that they “bleed” very badly. While they are in shelf storage, and especially once a tube has been opened and placed in a grease gun, the lubricating oil slowly bleeds out of the carrier.
Grease is simply an oil that has been homogenized in a thickener/carrier; whether Shell’s Microgel, or a lithium complex, or clay/bentonite, or whatever. A grease that is prone to bleeding lets the oil drain out of the carrier. Then you are left with a thickened and dried-out layer of gunk in the joint and fitting, that you can’t even get to move when you try to put in new grease. How many people have asked why they can’t get grease into the fittings on their plane? You also discover that you have oil all around your grease gun, or in the old sock you keep on the grease gun barrel; your grease gun won’t feed, and you wind up putting in a new cartridge. If the new cartridge has been on the shelf somewhere for months or more, it won’t be much better than the tube you take out; or not for long. I suspect that the more expensive synthetics may not be as bad about it, but I’m none too sure. The synthetic component most commonly seems to be the lubricant itself, as opposed to the carrier, and it looks to me like the problem with bleeding is primarily with the carrier.
A highly respected elderly A&P-IA (now deceased) once told me to never use those “obsolete greases” again, in light aircraft, when I could exercise the option. It isn’t entirely hyperbole either, as the MIL-Spec on which Aeroshell #5 is based is itself obsolete. Another factor is that #5 is incompatible with other greases, and an accidental mix (causing corrosion) might be outside your control or awareness. The man operated a seaplane business for many years, and said that his personal experience proved these specified traditional lubricants to be functionally obsolete in an era of more modern lubricant chemistry. He strongly recommended the following Kendall grease, as having a top balance of shelf stability, appropriate qualities, and premium water-washout and corrosion resistance. It seems to me to be markedly more “tacky” than the traditional Aeroshell greases, as well as being easier to work thoroughly into ball bearings.
Kendall L-427 Super-Blu:
http://www.kendallmotoroil.com/NR/rdonlyres/C9EBFC3B-3572-4628-BD58-C38D720F662F/0/K_L427_SBlu.pdf
I can tell you that the L-427 is reasonably available, especially in small tubs (though not from every source), and is reasonably priced. Most importantly to me, it doesn’t bleed out of a gun or separate out in a tub. Once I have successfully cleaned a joint and used it in that given joint, I never have any trouble lubricating that joint again. The new grease easily cleans out the old grease, carrying any contaminants with it. While Shell highlights their non-organic “Microgel” thickener that they use in most of their greases, I am highly skeptical about its ability to control bleed-out in seldom-used guns and infrequently-lubed joints. It is also interesting that Shell’s premium #33 grease, developed for Boeing for things like general airframe, bearings, and jackscrews, uses a Lithium Complex thickener… just like the Kendall Blu. The #33 meets the same MIL-Spec as Aeroshell #7 (MIL-PRF-23827C). Why did Shell need to develop a new grease to satisfy Boeing, when they already had one for the same military specification? There had to either be properties the #7 had that Boeing didn’t like, or the #7 was missing properties that Boeing required (presumably outside the
MIL-Spec). I did try the #5 and #7 in one other brand (it may have been Royal but I can’t recall for sure), but I didn’t like its qualities either.
In case you would like to try to compare the qualities of the L-427 and the typical general aviation greases, here are some links to some grease specifications. You can’t always get a direct comparison, as some of the ASTM testing is different between the MIL-Spec and non-spec greases. In some apparent key aspects they are almost identical (such as temperature range).
SSR Grease Link
http://www.sacskyranch.com/faq_grease/FAQ00002.htm
AST Bearings MIL-Spec Link
http://www.astbearings.com/p-lubes-greases.php
Shell Grease Specs
http://193.113.209.166/aeroshell/aeroshellgreases.pdf
If I try another Aeroshell grease, it will probably be the new Aeroshell 33.
Unfortunately I have been unable to turn up actual specifications for the Lubriplate 630-AA grease, recommended in the service book for some of the older Meese. I believe that the 630 series is one of Lubriplate’s oldest product lines, somewhat upgraded (at some point) based on the AA suffix indication. I can tell you, though, that in every tub of white Lubriplate grease I have had I have seen the darker oil settle out of the white carrier in the tub. I have not, however, ever noticed the remaining carrier stiffening up over time, as does the Aeroshell #5 and #7. If anyone finds specs for this grease, please send me the text or link. Please also let me know of any info you turn up that conflicts with my personal observations to date.