Get a new key from the dealer (or several if necessary) and toss any
brass duplicates -- they fill the lock up with shavings, believe it or
not.
If that doesn't cure it (and it probably will only help), buy a new
tumbler BEFORE it gets totally stuck -- they aren't expensive ($60 or
so) and it's any easy job UNLESS the key is totally immobile -- insert
key, turn to position 1, pull rosette up, turn key to position 0,
remove key and rosette, then insert key, turn to position 1 and insert
the "removal tool" -- depending on age, this is either a stiff wire or
a wire bent into a "U" with a 45 degree bevel on each end -- and
unlatch the tumbler. It will then come out with the key.
If you wait, it's about 4 hours of work, requires $150 or more in parts
(depending on what breaks) in addition to the tumbler, and you have to
grind the harded latch pin off with a Dremel tool, lying on you back on
the floor with the underdash panels out.
Peter
