TB3 Bearing

When I got my TB-3 new, it would to bind when I put weight on the top of it. I took it apart to see it I could fix it. What I found it inside really surprised me. The allen screw that holds the ball bearings in side was hitting the bearings. The bearings could not slide passed the screw.

Ok here is what I did to fix it:

Remove the Allen screw and let each bear fall through the allen hole, It's a good idea to have a cookie pan to catch these bearings as the fall out.

First thing, I replaced the short allen screw with a longer one, then ground off the bottom of it so that it would be flush on both sides of the bearing. This way I know that I have the allen in the right position when I re-assemble. I tapered the bottom edge just a little bit. Now the ball bearings can pass over the allen much better. The allen has a dimple in the bottom of it. By grounding away this dimple the bearings won’t catch and hang.

There is nothing holding the allen in place. In time the allen could move in or out. Thus the bearing would either fall into the hole or not pass over the allen. Either case the Thrust Bearing would fail. To fix this I drilled and taped a small hole through the bearing into the screw hole where the allen goes, I installed a second much smaller allen to hold the first one in place. I guess you could use lock-tight to hold it. But at 60' feet in the air...