Relay solenoid armature lubrication
 

Is it advisable to lubricate the armature of a solenoid.
as the starter on my car failed to engage, and after a tap it worked.
On the L1011 the pax door locks were solenoid operated and we were told never to lubricate the sliding plunger.
I took the starter solenoid apart and cleaned and polished it, and assembled it dry.
any info or regulations would be appreciated.

The armature should remain dry. Oil can collect dust and grime causing it to jam. The clearance between the solenoid and armature is very small.