Make sure the sides are centred and snap tight and bolted properly?
Undo break side seals and reseat.?
Check for a loose screws, washers or random crap inside motor? (Happened to me. washer)
Check for rogue stator coil former/s spread apart and you missed it..
If problem continues, maybe try some sand paper around the stator until it stops rubbing, not don't sand magnets. watch spreading the Coil formers and keep the dust out of the coils. Sand wipe and blow, keep it clean.
Give it a good wipe out before resealing and check magnets for chips and flecks of magnet.
When the MP is apart Magnets are great at sucking stuff up with out the user knowing.