Lock nut and screw adjuster.??.....How about drive gear back lash ......You have ventured into a very dangerous place my son....The window regulator on a hand operated system can be unforgiving let alone an electric one....BE CAREFUL !!!.......On the older vehicles with a wing window ..thats the first thing that has to come out...then the main glass....then the entire regulator..(scissor looking part).....ya then change the motor on the bench.... .....Frozen/missing/misaligned/ tract rollers.....missing/misaligned tract hardware.....felt runners galled up in the end tracts...foreign objects that have fallen into the regulator....and last but not least.......NO sign of lube ANYWHERE on ANYTHING.!!!!......It all puts too much strain on the already wimpy armature of the electric motor.... ......Just repaired a 1977 Ford T-Bird that the one of the mounting bolts for the rear tract was NEVER installed...It finally blew the rear roller off and let the window fall cattywhumpus into the door...Believe it or not FoMoCo still provided the rollers as a kit...I wonder how long a person at the factory lasts assembling doors....They are probably induced with some sort of mind numbing drug.!!!....