T-3's date decoder

[Joseph T.]

T-3's were date stamped on the back.

I have the date decoding chart for T-3's and I don't recall ever seeing it published.

Would the Judging team be interested in adding the chart to the judging manuals for reference?

Joe

[Terry M.]

Re: T-3's date decoder

Depending on how large the chart is, printing it in The Restorer would get the word out.

[Chris H.]

Re: T-3's date decoder

I would like to know. But could not be judged unless we start tearing cars apart. Can you tell me what mine are?

012/A14
012/A60
123/B30
123/C7

Thanks, Chris

[Gary S.]

Re: T-3's date decoder

Joe, how would a judge inspect the headlights without some serious disassembly of the headlight housing and trim? Other than taking off the air cleaner and dropping the spare tire carrier, we don't do any disassembly. I can't imagine that this would sit well with someone who has to break out his screw driver to show stuff. Neat information though.
Gary

[Robert C.]

Re: T-3's date decoder

There are codes, dates ,or ? on all T-3 faces right below the aiming tips. There's also a code @ the top center. When someone figures these codes out, then we can judge them.

[Joseph T.]

Re: T-3's date decoder

Bob

I studied this years ago and had that info but no one was interested. Now I would be pressed to find it. It seems to me that the lenses were made in male and female molds with one being called the plunger and yes there was some kind of date or control # used for each batch...and molded into the lense.

Regarding the assembly date code stamped on the back..I would not recommend adding this to be judged..but it might be a nice added feature for those who might be buying used T-3's and would like period or year correct bulbs.

Adding the chart to the manual would provide one more concrete piece of historical evidence.

I will find the charts and either post them on this discussion board and or send them to Terry to print in the Restorer so everyone can have it.

Joe

[Chris H.]

Re: T-3's date decoder

Joe, the numbers I left are molded into the rear of the bulb near the prongs. There are no "stamped in" numbers.

Chris

[Terry M.]

Re: T-3's date decoder

Chris,
The originals on my 1970 had a date ink-stamped on the back in orange. No code, just like: Dec 10 1969. Looked like a commonly available office supply stamp. This might have been an OEM only feature, I have never seen it on other than factory installed bulbs but I don't see enough of those to draw a conclusion.

[Chris H.]

Re: T-3's date decoder

My bulbs have no ink markings. Just the "cast in" ones I mentioned before.

[Kevin M.]

Re: T-3's date decoder

Sometimes when I clean the back of my lamps it removes the rubber stamped dates shown in the drawing above. But I've seen plenty with the stamp like described above.

Kevin

[Robert C.]

Re: T-3's

I collected 60-70 T-3s from a junkyard a few years back. All were from original GM cars. ALL of the bulbs had the orange date stamp on the rear face of the bulb as Terry mentioned. That's when I started looking at all the other cast-in codes on the front faces. There were NO TWO with the same number. I thought that was unusual.

I now wonder if those repro T-3s that are sold now have all the same casting codes or if they have any at all. That would be a quick way to tell on the judging field besides the DOT cast. I would look forward to seeing Joe's chart on the codes etc. Please try to find them. Thanks, Bob

[Bill H.]

Re: T-3's

The repro T-3 low beams can easily be discerned by looking at the metal baffle in front of the filaments.

In all my years (almost 20) of finding/cleaning/selling original T-3s I could never find any date correlation to any markings on the face of the unit; the date codes were stamped on the reverse in orange or (earlier) black. I did notice what I consider to be specific ways to identify (not merely vendor differences) low beam units for 1960 and 1971. I have no evidence other than my experience.