Packard Forum Index » V-8 (1955-56)

I received my replacement trunk lock cylinder. I want to rekey it by swapping the wafers from the old lock and putting them in the new one.

On the top, on both sides of the wafer slots, there are two very thin strips of metal - like a very thin straight section of a paper clip. It seems these are pressed into the cylinder housing to retain the wafers, so that the spring action does not push them out. They run on each side of the wafer slots from front of cylinder to back of cylinder. They effectively block the outside edges of the wafer slots to keep from removing the wafers.

I am a little leery of popping out these retainer pieces for fear of not being able to put them back in. Has anyone done this before and can offer advice/encouragement?

You can just insert whatever key you want to use and file the protruding tabs flush with the cylinder body. No need to disassemble anything. Don't recall what happens when you use the original key but I suspect it will work as well.

No, can't do that. Some wafers are not protruding but are in too deep. A real re-key is necessary. I was able to remove one of the little retainers on one side and am now fidgeting with the other one. It is in there very snugly, and I am afraid to break it.

I did was Dave described on my trunk lock and it worked perfectly. Its only the tumblers that protrude that keep the lock from turning. It doesnt matter if a few are below the surface.

True, you are correct. I wasn't wearing my logical hat. Well, as it stands, I popped out the retainer clips (basically a firm, little pair of wire as described), re-keyed the lock, and have re-inserted the clips.

There was a tiny little crimp holding the clips in their grooves. By popping them out, I obviously widened the gaps at the crimps, so now they do not hold nearly as solid. I am eyeballing just how I am going to re-crimp. I definitely don't want to damage the cylinder, but it seems I need to hold the cylinder firmly in place and maybe tap at it with the corner of a wood chisel. The corner of the chisel blade may spread a little of the metal over the groove.

Jeff -

What you did is similar to what is still being done done with late model cars - though the retainers for the tumblers (wafers) have changed over the years. Generally, you would install new tumblers in a new cylinder, but we don't have that luxury with the old Packards.

Working at a GM dealership decades ago, I often had to re-code old lock cylinders at the request of second or third owners of a vehicle (back when it was cost effective). The relatively soft metal of the lock cylinder could be re-staked using a punch or chisel (depending on the type of retainer and the amount of material being staked). Don't hit it too hard, though - in case you ever need to remove the tumblers again.

Filing the tumblers flush, as described, above is another method that will work with these old lock cylinders, but I personally prefer swapping the old tumblers like you did.

Although you'll find a lot of great info in the factory shop manual (archived on this site), this is one of a handful of little things that they didn't cover.

Okay, we're done. I am looking forward to re-installing the trunk lock assembly, so that my trunk will finally lock again. Because the nipple broke off of the back of the cylinder, the key would turn, but without the nipple, the cylinder would not engage the locking bar.

How often are keys repeated????? I have no documantation but according to one reliable source ca. 1970, Chev. repeated keys every 1000 keys during the 1940's-60's time frame.

I saw a Chev. rep one time with a key hoop about 2 feet in diameter full of keys.

I don't know, but there would be no reason in my mind to use as many variations as the lock will allow, less certain unworkable ones.

For example, let's say there are 5 wafer slots. For each wafer, you might have 6 different depths. So, you could have 6^5, or 7776 different combinations. Of course a combination with all 1's is not a very good one, just like a combination with all 2's is not very good. So, I'd suppose you'd have to exclude a good handful of combinations.

Six different heights and 5 wafers would = 30 different keys.

When a wafer is moved by a WRONG key tooth it mite release at the top but then stick down thru the bottom thus remaining locked. SO a wafer can lock at 2wo different places, bottom or top. That would be the equivelent of 10 wafers releasing only at the top.

10 wafers, EACH WAFER with only 2 possible results (on or off) would be something more like 2**10 + 1. A little over 1000 if i do the arithmatic rite.