Packard Forum Index » V-8 (1955-56)

I queried another 56 owner and he had no idea either.
I have often wondered about these rectangular holes as I have never found a speednut on the backside.
The screws are listed as G162479 in 4.1600 but I can't find them in 50.303 which is where I thought I would find them.

439869 seems to be the speednut required but is only listed for the 5580??
It's a puzzlement??

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I thought they might have originally planned on a cage nut and later went to something different. Wasn't sure what size. IIRC, the holes are a bit large for a modern 8 or 10 size nut assy. Perhaps the cages were larger then or the hole could have been sized for a piece unique to the auto industry or to Packard.

I ran into something similar on the 47. It has a couple of square holes where cage nuts are used on the top fender to cowl attachment bolts. The nut on one side was missing and when trying a modern nut, the width of the ears was a tad small for the square. I had to widen the nut cage a bit so it would stay in the square and not be pushed back when inserting the bolt.

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The screws are sheetmetal thread, NOT machine thread.

I was thinking originally they planned the nut and thread but went to something else easier or cheaper after the dies with the square hole punches were already made for stamping the metal. Rather than the expense of reworking the dies for such a minor change they just did a workaround.

Doesn't the top screw for the 56 Sr. headlamp bezel thread into a spring steel nut set into a similar (but smaller) square hole in the underside of the fender brow?

Brian, yes and that is a good point. Apparently that was also the thinking for the taillights, but wasn't carried through. I am going to look at my Patrician to see if it is different.

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Not all snap-in cage-type nuts were machine thread. There were also clip-in type Tinnerman nuts (what the people in this forum refer to as "speed nuts") that were used in such applications. These anchor nuts I describe took a sheet metal type threaded fastener or screw. These Tinnerman nuts were used in making everything from aircraft to cars. Of course Tinnerman nuts sped up assembly processes so well during WW2 that they became probably best known as "speed nuts"...and they actually came in both flavors: machine thread and sheetmetal thread.

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I know. I've used both types many times. The question was why the square hole in that fender location and was there a special clip or nut used.

Most of the Tinnerman or speed nuts we are familiar with today just clip over a straight edge or are just a flat rectangle which lays over an opening. Usually there is a simple hole in the metal so the screw can go thru that hole and into the nut for maximum support. Those wouldn't require a square hole and a smaller round hole would probably be easier to punch or drill. In fact, the square hole makes installation more difficult for the clip on type. It is also a bit weaker when using the clip on type because one side of the nut is not well supported.

Randy has a good question. Did Packard use something not found as easily today or just use the flat type and hold them in position over the square by tape or some other method while the screw was inserted? That was the method they used on some dash speed nuts where access to the nuts was restricted

Samples of 439869

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Yes, that is the speednut for the headlamp door, BUT that speednut is only listed for the 5580 taillight, NOT for the 5680??
AND the screw for that speednut is not listed in 50.303.