I had to remove the set screw from the top brush cover of a Lionel Pullmor motor (1983) to oil the upper armature bearing & shaft. What is the general rule for tightening this screw? The instruction sheet says “tighten until snug & then back off a 1/2 turn”. How critical is this adjustment? Can it cause wear if it’s not perfectly adjusted? Lots of creeping doubt entering my mind after making the repair. Thanks.
-B in B