On Sun, 25 Aug 2019 17:40:19 -0500, dpb wrote:

Some time back I posted a query about the issue of having to jiggle the
ignition switch on the old '98 Chebby pickumup to Clare as to whether
symptomatic of key or lock. Suggested lock if key works in door; turns
out did so finally(!) got the round tuit and swapped out for new
cylinder this afternoon.

Works quite well but the annoyance factor is quite high in the doing it
phase with the fact GM didn't split the top/bottom halves of the cover
around the switch until at least '99 as the earliest--this thing has to
be prized off over the key cylinder in place which is no treat. Plus,
there's a two-piece stud holding the top LH side in place that turns but
doesn't release that a video shows was replaced by a long single
fastener later as well...

But, aggravation aside, can report is done and thanks! for the
diagnostic info so knew which way to go. Don't recall having had
another wear to this extent to being such a pain altho have had many
vehicles far older than this...dunno why this one was so hard. A couple
times in town wasn't sure was ever going to get it to turn -- about 2-3
full minutes of messing around was finally the straw to send me to NAPA
last week!
GM has had an issue with this for decades It is made much worse when
you have a heavy ring of keys hanging from the cyl.