Fuel pump locking ring not screwing on
 

Took me several hours to get the locking ring off, eventually managed. Replaced fuel pump and went to screw brand new locking ring back on (OEM, matching part number to the old one) and the threads won't catch. The new pump is seated properly. When I try to screw the new locking ring on it just spins and spins and won't catch on anything. I lubricated with silicone and have been trying to screw back on for a few hours now. Help please!