Pitted races

Well, this weekend I wanted to get the tailwheel built up and mounted on the airframe so I can roll the darn thing around. Well as I gathered all the pieces together and started a final inspection, I noticed the Scott 3200 wheel bearings were pitted.

Next comes the research to replace them. The Bearings are Timken A4050’s with a race A4138. Looking at the regular places like Univair, Aircraft Spruce and others, these bearings are very costly considering their size. To get the Bearings, races and dust covers is over $270.

If you look up the timken A4050 on its own, you can find the bearing for MUCH less, like $40 for two bearing and race sets!

So now you are asking why? Why are the SAME bearings 1o times more expensive from the Aviation parts houses? Well I found an interesting post on this McFarlane site stating that the Aviation grade of the A4050 actually has a part number A4050-20629.
https://www.mcfarlaneaviation.com/products/product/A4050/

You can see that the A4050-20629 has the FAA/PMA stamp and appears to be a black roller cage.

Will Ware

Author: Will Ware

I live in Rockwall Texas and I’m rebuilding a 108-1. I’m a Captain at Southwest Airlines but I LUV taildraggers.

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