Bruce took the wheels apart so we can do a dye penetrant test to ensure the wheels are still in good shape. Since another IAR had a problem recently, we want to be sure to fully inspect everything! There will be more posts detailing other areas, but the wheel bearings are an interesting piece that deserve a post of their own. 

We wouldn’t have thought much of what we found except that we read up on what to look for when inspecting bearings. We found grayish black streaks on the bearing cups in the wheels that matched the spacing of the rollers.  

This was our hint that we need new wheel bearings. Those marks indicate that water had been in the bearings. This is one of the best guides to inspecting bearings that we have found. It includes pictures of what to look for and what it means when you see certain signs. I will definitely be browsing their other topics as we go through this restoration and highly recommend them:  http://www.flight-mechanic.com/aircraft-wheels-wheel-inspection-part-two/

Knowing we needed to replace is a great start. Where do you go to find them? It is difficult (and expensive) if you are buying bearings for an airplane but if you are looking for bearings for your race car…  I was able to take one of our bearings in and have them match exactly what we have. It isn’t anything uncommon so you can take the product information and just buy one. 

Original bearing is on the left and the new one is on the right.

Timken X30208M  The new ones ran about $35 each and came with bearing cups.

We haven’t installed the new ones yet, but I ran across a link with great directions on removing the wheel bearings and helpful pictures to make sure it all goes back together correctly. Should be useful: https://www.cessnaflyer.org/maintenance-tech/item/1168-diy-wheel-bearing-service.html