73-87 Chevy _ GMC Trucks > Projects Posts (NOT VEHICLES)

Ignition key/lock swap & upgrade.


Mr. Machanic:
I just picked up this 79 Big 10 last weekend.
It's my first and I smile every timeI think about it.
Apparently, the original ignition cylinder had been replaced years ago.
But I only got 1 key when I bought it and the operation of the unit was sketchy at best. Always had to jiggle and wiggle the key just to get things to move.
I decided to replace the cylinder and the new one came with 2 keys.
I've never tore into a steering column before, so this was new territory.
I brrowed the puller and bought the spring/plate compressor., $15.00 @ NAPA.
The horn button had 2 tabs broke off (I'll repair that some other day) and pretty much jumped into my lap.
The whole assembly came out without any real issues, other than that "C" clip. It was a bit of a stinker, but eventually cooperated.
To my surprise there was no cross bolt, holding in the cylinder. A push on a little plastic tab an the cylinder slid right out. No wonder a slide hammer jacks one out in about 5 seconds. This just will not do.
Prior to starting this project, I had read a fee "how to's" and they showed a cross bolt being removed to allow the cylinder to come out. Seems like a way better idea instead over that chinsy plastic tab.
The challenge will be locating the hole that needs drilled for the bolt. Gotta get it right the first time. No room for error. No pressure.
As you can see in the pictures, the new cylinder comes with a notch for the cross bolt.
So after taking some measurements and guestimating the location of the new hole, I packed the are with some gauze. That will keep the chips from getting where thay ain't wanted. The cordless drill had an undersized drill chucked up and a pilot hole was soon drilled thru into the cylinder bore.
That's a good sign. At least we're in the ball park.
The cylinder was slid in and hole placement was very close. The drill bit for the 10-32 was chucked up and followed the piolt hole. Then it was tapped and the chips were vacuumed out.
I had to file a bit of the notch to get the screw all the way in, but no big deal.
Everything was reassembled and presto ignition cylinder upgrade completed.
A slide hammer might get the inner cylinder part out, but not that cylinder housing. Besides it works much smoother, just like it should.

Mr. Machanic:
Prior to upgrade...

Good job Mr. M!

Looks threaded, but you didn't mention it.

Also like your detailed execution-good stuff.

Mr. Machanic:
The "10-32" is the size of the threaded hole. Basically a 3/16" diameter set screw. And when you hear of a hole being "tapped", it means they put threads in the hole.
Sorry for the shop vernacular.

I did forget the trucks description,  so here goes:

 I am the 3rd owner of a 1978, Big 10.
88,K miles.dark metallic brown, red interior.
350 with turbo 350.
Unmolested and bone stock.

Did I forget anything?

Um, yes.

PICS!  8)


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