The International Cessna^® 170 Association

How about a little input on greases ...
What brand / type for the tailwheel?
I need to grease a bushing on the RV before final assembly ... it is a brass bushing in a steel fitting and they say "lubricate with your favorite grease prior to assembly" - problem is, I don't have a favorite grease.

Thomas

MIL-G-81322

Mobil 28 or Aeroshell 22 are good choices. I use the Aeroshell 22, it's a wide-temperature range synthetic. The synthetics have more stability than the organics in that wide temperature range.

Stands up well in the harsh environment.

MOREY'S® SUPER RED -PREMIUM WATERPROOF GREASE

http://www.moreyoil.co.nz/details.php?& ... oductID=13

I get it at NAPA for $6.00 a tube


Dave

Synthetics are tolerant of neglect. But they are especially IN-tolerant of mixing with other greases. (Most greases do not mix, unless they are of the same base-type, ie Lithium, Calcium, Aluminum- complex, etc.... but Synthetics are especially intolerant and mixing with mineral greases will rapidly lead to failure.) For that reason, in applications such as aircraft, which typically get regular attention, I avoid Synthetics.

Cessna and most other light-plane mfr's allow any good quality grease produced by major refiners that meet automotive standards in similar service. There is ONE thing that virtually all airplanes have in common... bearings that are NOT sealed well against the environment, and which are exposed to water hazards,....(washing, pressure-washing, taxying thu puddles, etc.)..., and which also are subjected to wide temperature extremes, ... and also may get subsequent service from different persons unfamiliar with specifications of previous greases.

There is a readily available grease which meets all the criteria for the mfr and for the service intended, and which readily mixes with most common greases, is temperature tolerant, extreme-pressure adjusted, and is virtually waterPROOF... It is Marine/Boat-Trailer wheel bearing grease. It is usually a Calcium-based waterproof grease (read the label to be sure you are getting the right stuff), and can be found at WalMart, NAPA, AutoZone, CarQuest, Marine/Boat dealers, etc etc. It is available in large cartridge, and also small grease-gun cartridges, and 1 lb. tubs. Not always, but usually green in color... but I like it anyway.

Food for thought:

A boat trailer rarely goes from 0 mph to 60 in an instant like a landing aircraft wheel does. Aviation grease is made for that application, and a tube of grease lasts so long the cost is nominal over the long haul. The savings from using boat trailer grease wouldn't add up to much.

All old grease should be removed anytime a bearing is serviced.

If you were on a trip and someone at an FBO serviced your bearings, it seems much more likely that they would use Aviation grease vs boat trailer grease, if that is what you are talking about on contamination.
It would be even more critical on higher performance planes than the slow landing 170.

I would guess that either grease will perform the job, the most critical item is regular maint. By the way, the Shell 22 is listed as having excellent water washout resistance!

Aviation grease is fine in a dry and or cold climate. But it is of little use preventing bearing rust in a wet climate. Learned that many years ago. I prefer a stringy, sticky, grabs ahold of everything it touches waterproof grease. And I fill the tailwheel full of grease so water cannot have a space to enter. Around here lots of puddles when it isn't snow.

N1478D wrote:...A boat trailer rarely goes from 0 mph to 60 in an instant like a landing aircraft wheel does. Aviation grease is made for that application, and a tube of grease lasts so long the cost is nominal over the long haul. The savings from using boat trailer grease wouldn't add up to much.

Boat bearings get wet and run for miles and miles and miles... after being submerged in chilly water. No savings are expected in the price of greases.

N1478D wrote:...All old grease should be removed anytime a bearing is serviced. !

Yep. Always good advice.

N1478D wrote:...If you were on a trip and someone at an FBO serviced your bearings, it seems much more likely that they would use Aviation grease vs boat trailer grease, if that is what you are talking about on contamination.

If the above is performed, (old grease removed) not a problem.

N1478D wrote:...It would be even more critical on higher performance planes than the slow landing 170.

My fondness for marine grease is it's waterproof characteristic.

N1478D wrote:...By the way, the Shell 22 is listed as having excellent water washout resistance!

All greases make that claim. Try washing your other greases off your hands with ordinary water, and then try washing marine grease off, and you'll likely see the difference.
You are correct, ... as Cessna says,..any quality grease will do.. But water PROOF grease seems better to me than water resistant.

I am not against the boat trailer grease. The question was asked about one's favorite grease, and I replied. Mine is the Shell 22. I have to taxi thru water at times at the smaller strips. Every year at annual, all of the grease is still in there, and there has not ever been any rust. Here in North Texas, it is mild conditions compared to what has been described in Alaska. So, my experience with Texas conditions has no relation to those operating in harsher enviornments. Shell 22 might not be the right choice in those conditions.

What is your opinion of this scenario:

Upon landing, a wheel bearing freezes up (or brake pad breaks, etc.)and causes you to veer off the runway and onto the ramp where you slice an 8 million dollar jet in two. The lawyers look thru your log books and discover that you use boat trailer grease vs. aviation grease (or they discover it upon wheel examination). They also know that aviation experts, such as LPM, have multiple times in print advised strongly against using boat trailer grease in airplanes. They now feel they have you and are going to add the millions in opportunity costs that the jet will loose in income till the owner can replace it!

Not wanting to be argumentive, just very curious. It seems like the lawyers could and would, rake you over the coals if they found any thing that wasn't made for aviation. The odds are pretty small that it would ever be an issue, I understand that. But, my life experiences every once in a while follows that Murphy rule!

N1478D wrote:I am not against the boat trailer grease. The question was asked about one's favorite grease, and I replied. Mine is the Shell 22. I have to taxi thru water at times at the smaller strips. Every year at annual, all of the grease is still in there, and there has not ever been any rust. Here in North Texas, it is mild conditions compared to what has been described in Alaska. So, my experience with Texas conditions has no relation to those operating in harsher enviornments. Shell 22 might not be the right choice in those conditions.

What is your opinion of this scenario:

Upon landing, a wheel bearing freezes up and causes you to veer off the runway and onto the ramp where you slice an 8 million dollar jet in two. The lawyers look thru your log books and discover that you use boat trailer grease vs. aviation grease (or they discover it upon wheel examination). They also know that aviation experts, such as LPM, have multiple times in print advised strongly against using boat trailer grease in airplanes. They now feel they have you and are going to add the millions in opportunity costs that the jet will loose in income till the owner can replace it!

\
If boat trailer grease is the only grease in your wheel bearings, they will not fail because of the grease used.
I didn't know that LPM experts advise against boat trailer grease. If I did know it, I'd ignore that advice. Cessna approves it. The mfr of the bearings (Timken) approves it also.