Grease Guns

I'm a few months away from my first condition inspection, and I have a dumb question about grease..

The prop gets different grease (Aeroshell #6) than the wheel bearings (#5, or #22, or Mobil #28, or whatever from the auto parts store). Do I need to buy two grease guns to avoid inadvertent intermixing, or is there a way to thoroughly clean a grease gun and subsequently use it with a different kind of grease?

Also, if I don't need to replace the tire or tube, is there any reason to separate the wheel halves for a proper bearing grease job?

Thanks.

[frankh]

Buy a cheapo grease gun for like 10 to 15 bucks from the autoparts store and dedicate it to Aeroshell #6...The mess you will make in trying to use one gun for different greases will be beyond belief..You'll make a big enough mess as it is..

Why do you need a different grease gun anyway..The only other grease nipple I'm aware of is on the nose gear fork..I.e the wheel bearings get packed manually..i.e no grease gun.

Frank

[Kyle Boatright]

Originally Posted by Geoff

I'm a few months away from my first condition inspection, and I have a dumb question about grease..

Also, if I don't need to replace the tire or tube, is there any reason to separate the wheel halves for a proper bearing grease job?

Thanks.

This may be sacrilege, but numerous A&P's and IA's I know say aircraft wheel bearings are the most over-serviced items in the world, and don't see a need to service them between tire rotations/changes unless the wheels have been underwater (ex: SnF this year).

If you think about it, back when cars had wheel bearings that needed maintenance, that was done every 3,000 - 12,000 miles or so, depending on whose manual you were working out of. My airplane wheels probably won't see 1/10 of that use in a year. So I only deal with the bearings when I rotate the tires every 100 or so hours.

But to answer your question, a grease gun isn't going to help you service the bearings in the wheels. That grease is hand packed into the bearings with the bearing has been removed from the wheel and cleaned.

[gasman]

Originally Posted by Geoff

If I don't need to replace the tire or tube, is there any reason to separate the wheel halves for a proper bearing grease job?

Thanks.

THE ANSWER IS....NO!

The bearings ride on the outside of the wheel assy. The bearings just pull out with the wheel removed from the fork, or there is a retainer ring that you pry out with a small scewdriver to remove the dust seal and the bearing will then just fall out. STA-LUBE BOAT TRAILER GREASE from NAPA AUTOPARTS comes in a can, and works just great for small aircraft wheel bearings. A can will last you about 20 years..........

[rvbuilder2002]

Originally Posted by Kyle Boatright

This may be sacrilege, but numerous A&P's and IA's I know say aircraft wheel bearings are the most over-serviced items in the world, and don't see a need to service them between tire rotations/changes unless the wheels have been underwater (ex: SnF this year).

I totally agree.
I do maint. on a number of RV's and the wheel bearing service/greasing interval I use is when ever a tire get replaced (unless something adverse happens such as the submersion you mentioned).

Originally Posted by frankh

Why do you need a bifferent grease gun anyway..The only other grease nipple I'm aware of is on the nose gear fork..I.e the wheel bearings get packed manually..i.e no grease gun.
Frank

I was thinking about the nipple on the top of some of the wheel bearing packing tools (like the one Avery sells) -- but the auto store packing tool that I'll probably buy probably has no nipple on it. So that's a good point you make.

Nose gear? What's that?

[frankh]

Originally Posted by Geoff

Nose gear? What's that?

The thing I wish i didn't have!

Frank

[Rick6a]

I suspect for the most part, wheel bearing grease changes became informally codified as a "check mark" item routinely addressed as part of an annual inspection. I agree with Scott and others, unless the bearings have been submerged or otherwise subjected to harsher conditions than a routine operations off of paved surfaces, the need to change wheel bearing grease at every annual or condition inspection is....overkill.

Further, I am of the school that believes it is *probably* (weasle word) best to use a wheel bearing packing tool to simply displace the existing old grease with new as opposed to cleaning or soaking the bearings in solvent.

[AMURRAY]

I am not one of those A&P's. If water gets into the bearings it will not take long before they are shot. If careful it is hard to get water into the bearings. It is easy to do if the wheels get sprayed with a water hose when cleaning. Fortunately most RV's have wheel pants. Just did an annual on a plane that had been stripped and painted, including the Cleveland wheels. I am assuming that the paint shop used a pressure washer. All of the bearing cups had black stripes, so six new bearings and six new cups. With bearings at $25-$30 each and cups $15-$20 each it ads up.