Landing Gear Bearing Re-Grease

[jiott]

Just curious what others are doing on this subject. My Kitfox factory checklist for the annual condition inspection calls for the main landing gear bearings to be inspected and regreased every year. This requires removing the wheels from the axles, taking out the bearing retaining snap rings and collars, and removing both bearings to be cleaned, inspected and regreased. This is a lot of work and seems like overkill for something that in the automotive world goes for many, many years before servicing wheel bearings. What I have been doing annually is just jacking the tire off the ground so I can spin it by hand and check for freedom, smoothness, lack of funny noises, and lack of free play on the axle. I only do a complete bearing removal & regrease when I install a new set of tires, which happens about every 5 years. What are you all doing?

P.S. On the tailwheel, I add some fresh grease every annual using the convenient zerk fittings.

[Kitfox Pilot]

My mechanic told me years ago that the bearings need greased when the brakes or tires get replaced. He did jack them up and roll them to feel for any rough feeling. He did that on my archer for the last 30 years and it never had a wheel bearing replaced.
My Kitfox brakes lasted 350 hours so that's when I regreased mine and they didn't look like they needed it. JMO

[jiott]

My feelings exactly.
Thanks Harlan

[alexM]

Modern day automotive wheel bearings are completely unlike aircraft (and old school automotive bearings). I'm old enough to have owned some seriously old s***. Modern vehicles use massive roller bearings which are sealed and pressed into the hubs. When they begin to make noise you either replace the entire hub with the bearing in it, or you have a machine shop press the old bearing out and press in the new one.

Old vehicles use tapered roller bearings which have tapered "races" which need to be tapped into place in the hub. It doesn't require a hydraulic press. The bearings last for many years if you take the time to disassemble, clean, inspect and repack with fresh grease. Many fewer years if you ignore them. It's not that hard and most of the time doesn't require any parts. Eventually you'll see wear on the bearing races and you replace everything.

Part of what you're doing is making up for the wear in the tapered bearing by adjusting it all when you put it back together.

Cheap and easy. Not the same as your car.

[airlina]

When you think about that poor tailwheel back there spinning like crazy and getting beat up, I always give it special attention . keep it greased and tire rubber condition and a good look at my leaf springs , all AN hardware (have had some bolts shear) and component attach points under the fuse. Had a failure a few years back on my Series 5 of the fuse tab that hold the leaf springs and had to add the gusset that the new models already have. Bruce N199CL

[Dave S]

Jim,

My sentiments align very close to yours. I found that yearly disassembly, cleaning and repacking of the main wheel bearings to be excessive and unnecessary maintenance. I also jack up each wheel at least annually to check for smoothness, play and runout. I go with 5 years for a reasonable interval on routine main wheel maintenance.

Can't speak to tailwheel maintenance experience since I don't have one; however, pals who do have them do frequent maintenance.

I can speak to the nose gear/wheel and that is different on a kitfox since the bearings are not serviceable. The nose wheel appears to be aluminum rather than magnesium so maybe not as durable as the mains. Nose wheel bearings can only be checked for smoothness, play and runout and that is about it. If a person has any doubts, the wheel and bearing assembly is so inexpensive replacing the whole thing would not be a problem anyway.

I have determined that the front fork does need to be removed annually to clean the stub, fork bushings, washers and apply new grease. Moisture and dirt can work its way into the assembly pretty easily and if allowed to sit is a setup for corrosion.

Wrench well, fly well

[PapuaPilot]

I used to it do my bearings annually, but now it's every 2-3 years. A couple of times I pulled a bearing out and just put it back as it looked great and had plenty of clean grease.

FYI I have been using the blue boat trailer grease for years. t works great!

[Dave S]

FYI I have been using the blue boat trailer grease for years. t works great!

Papua - I did not mention it; however, I use the same stuff you do - best ever for wheel bearings - moisture resistance in particular

[jiott]

Thanks everyone for the very helpful responses.
Can you give a brand & part number for the blue boat trailer grease.

[PapuaPilot]

This or similar