What was found
(CAN) ON CLIMBOUT RT GEAR DID NOT INDICATE UP & LOCKED & INTRANSIT LIGHT ILLUMINATED. GEAR EXTENDED, THIS TIME GEAR DID NOT INDICATE DOWN & LOCKED & INTRANSIT LIGHT REMAINED ILLUMINATED. UPON LDG RT MAIN GEAR COLLAPSED. LDG GEAR ACTUATOR REMOVED & SENT TO TSB LAB FOR ANALYSIS. IT DETERMINED THAT THRUST BEARING IN ACTUATOR WAS INSTALLED BACKWARDS. RESULTING FAILURE OF THRUST BEARING CAUSED TEETH ON PINION & RING GEAR TO FAIL.