Wheel Bearing Inspection pics

[GAHorn]

When you inspect your wheel bearings, look for the following problems. Carefully study the pics and use a magnifying glass to inspect your bearings.

http://www.timken.com/en-us/products/ma ... s/6347.pdf

[ronjenx]

Thanks for the link, George. I saved the pdf and will send it to the guys in my old shop (KC-135 Repair & Reclamation/Wheel & Tire Shop).
Over the last 26 years I have seen almost all of what is in the pdf. We turned to Timken bearing exclusively about 12 years ago because they lasted through many more cycles than all the other brands.
My brother's 170A's wheel bearing get inspected/repacked every annual. They have lasted many years.
Thanks again.

[HA]

if your airplane sits tied down, rocking in the wind, then you should definately still clean and repack the bearings every annual. Even though you'll think that it didn't fly enough to "wear out" the grease, that's not what you're inspecting for - the bearings can fail just from sitting without turning from corrosion. Eventually they'll get noisy and you'll feel it when the wheels are rolling. remember, those bearings take a tremendous hit just in normal use, on landing they have to spin up to 60mph or whatever RIGHT NOW. pretty tough duty, takes me a couple cups of coffee to get moving at any speed usually

[bsdunek]

Right, HA, Loading non-turning bearings is very hard on them. Years ago, when I worked at Ford, we had trouble with Lincoln and Thunderbird front wheel bearings only on cars on the west coast. There was only one plant, Wixom in Michigan, that made these cars, so they had to endur a train ride to the west coast. Turned out the hammering they took on the train without rotating was damaging them.
A tied down airplane rocking and banging around in the wind might be a similar situation.

[170C]

I always clean & repack my wheel bearings at annual, but just wonder if I am alone having difficulty getting new cotter pins in the axels? Makes me want to use the old ones a couple of times rather than fight, cuss, etc. to get the new ones bent just so-so to go through the second axel hole/opening. Been fighting this for 25 years. Maybe someone has a "trick" that me and my neighbors haven't heard about.

[GAHorn]

Bend a 30-45-degree bend in the new cotter about it's mid-point. Insert it all the way TO the bend then, using the axle-hole you just inserted it into as a resistance-point, straighten the cotter again by taking out the bend. Finish inserting the cotter and cut off the excess with dike/cutters. Simple, eh?

[170C]

Worth a try George. I have had them that almost fell into the hole, then others that resulted in a second or third cotter pin before I held my mouth correctly. Its a project for a couple of weeks from now.

[Robert Eilers]

What type of solvent is best for cleaning the wheel bearings before repacking? I have been just forcing fresh grease through thr bearings.

[jrenwick]

What type of solvent is best for cleaning the wheel bearings before repacking? I have been just forcing fresh grease through thr bearings.

A spray-can of brake cleaner works very well.

John

[ronjenx]

What type of solvent is best for cleaning the wheel bearings before repacking? I have been just forcing fresh grease through thr bearings.

Does that mean you have not been inspecting them?
When I don't have access to a tank of PD-680, I use kerosene, a soft brush, and compressed air (don't spin them, and use eye and hearing protection). A petroleum based solvent will leave it's own clean residue (virtually invisible) for corrosion protection if you don't get to repack them right away.
As to the cotter pin at reassembly, if I don't have any that are long enough, I use two short cotter pins. I have also used two small nuts and bolts per axle. Nuts to the inside of the axle. Effective and re-usable.

[GAHorn]

I don't like to use aerosols on bearings because the propellant chills the bearing and attracts condensastion (i.e. rust). Mineral Spirits are an Excellent cleaner you can buy at any paint store or WalMart, Home Depot, etc.. WD-40 will work. (Remember, I buy it in gallon cans?) But kerosene, diesel, jet-fuel and of course STODDARD or any safety solvent or naptha. (Gasoline will even work, but it's dangerous.)