The failure of filter wheel no. 2 in May was relatively shortly after a complete overhaul of the bearings using new commercial bearings. After an extensive review we decided to return to the original method we used with standard SKF bearings cleaned and treated with MOS2 in-house. We know that with this solution bearings can work up to a couple of years, and in the future we just need to change the bearings regularly. As a modification the housings for all the worm gears were replaced with steel ones to give them the same expansion and heat conduction coefficients as the bearings.