Wheel Bearing question

[Paul 5r4]

I just completed the first condition insp on my 7A. Also I just got the plane back from the paint shop a couple weeks ago. I did notice that the landing gear/wheels were making a "different" sound than what I was accustomed to hearing since my first take off coming home from the paint shop. Ok, now back to the condition inspection. I pulled the wheels off to inspect, clean and repack wheel bearings. This is what I found. On three of the four bearing surfaces, these marks. I can feel nothing when wiping my finger over them. Interestingly, the bearings that came from each of the affected spots were a darker color than the "shiney" new look. the bearings look normal otherwise. When the condition insp. was completed and I flew again, the sound is still there... it's kinda of a "ZZZZzzzzzzz" sound that get higher in pitch until I lift off then of course it stops. Same thing on landing. What in the world is going on??? Could the surfaces have been "etched" or something during the paint/wash down or something? Could this cause me a problem like a freezed up bearing during takeoff or landing... that would be bad! Not likeing the idea of the cost of new wheels either!!! Just wonder what has happened. Any thoughts certainly appreciated.

[IMG][/IMG]

[bird]

I would try cleaning the race with solvent to remove those marks. The race should clean and very smooth. Repack them well and see if that solves the problem.

Bird

[Walt]

Hard to tell from the picture but I would suspect a form of brinelling or perhaps some kind of corrosion/etching damage.
You can replace the bearings and races.

Some good info from Timken.

http://www.timken.com/en-us/products...ochure5892.pdf

[rocketbob]

You need to replace the bearings and races, they're brinnelled badly. You may be running the nut too tight and as the wheels spin the heat generated by the bearings causes everything to become too tight.

[Paul 5r4]

Walt, thanks for the fantastic link! Lots of VERY good info there! Where would I find out about replacing the races? Are they pressed in or something?

Thanks again.

[AltonD]

I have to ask: How do you replace the race? Is it just pressed in?

[Paul 5r4]

Bob, Thanks for the post but the nut is not too tight. It is exactly where it was, I marked it before removing, the entire first year of flying. Wheels spin freely.

Thanks.

[qtrmiledan]

Looks like water/ wash damage- Had the same thing happen when I had my cherokee painted 5 years ago, had to replace them.

[aerhed]

You need a hammer and something similar to a big dull screwdriver. If you lay a wheel half on wood or something with the inside up you can see the edge of the race (cup) in the axle hole. Use the screwdriver/hammer to knock it out by going around hitting a little bit here & there so you don't get it cocked. After it falls out, grind the OD of the old race so it will fall into the wheel easily. Use this on top of the new race as you go around knocking in the new one. Knock it in until the sound tells you it's evenly and fully seated all around.

[Paul 5r4]

Thanks for all the replies. I've already taken the wheels off and will be replacing with new Bearings tomorrow.