I have a 1975 rolling chassis that I need to purchase a engine and transmission for. My plan is to do a -6 conversion and I think I have located a tranny but need to confirm with you experts. The seller believes it is off a 1973 but is not sure as it was part of a "lot" of Porsche parts he purchased. The number on the case is HA 23 02 per emails I've had with the seller, does this number confirm anything? From the pics he's sent it is a side shifter. Any help you guys can provide is appreciated. Thanks

That's missing a digit or three.

Up through somewhere in the 73 model year, the transmissions were labeled with "HAO ### ###". The rest of the 73 model year, and later, were labeled "HA ## ## #".

The early ones were "series numbers", in that they went from 1 through whatever, with each transmission assigned a unique one.

The later ones were date codes. I think the first two ## were the day of the month, the next two ## were the number of the month in the year, and the last one was the last digit of the year the transmission was built. (So many late-73 transmissions would end in "2", though the very late ones would end in "3".)

You can find a table with the transmission numbers here:
http://928porsche.net/history914w.htm

This info used to be available elsewhere, but I haven't seen it anywhere but on that 928 site in a while. We should probably have the info available here on the Club site...

--DD

Dave according to that chart the tranny might be a HA 23 02 3 which would mean it's a 73 from a 2.0 correct? I'll try to clarify with the seller but it appears the number combo of HA 23 02 ? is definately a 73 don't you think? And thanks for the response.

Dave,
What about this number? HB22053. The tranny came out of a 1974 parts car with a 2.0 motor.
Thanks,
Jack

HB? Not shown on the chart, which is my sole source of info on this. (And my vague memory that the other charts I've seen were the same as the one linked to in my post above.)

As for the number parts, I will explain again... From mid-73 onwards, the numbers were "DD MM Y", two digits for the day of the month, two for the month of the year, and one for the year. So, rfuerst, your transmission could be 23 February 1973, or 1974, or 1975... Maybe even 76?? And Jack, your transmission seems to have been assigned a number on the 22nd of May, 1973.

I am not at all certain how the date code relates to the completion date of the car as a whole, or if there is any specific relation. (I'd bet that the transmission date codes are earlier than the chassis date stamps, but that's about all.)

I hope this helps.

--DD

Here are the tranny code decoders from my collectibles webpage...

An HB trans is an LSD trans, but only offered in 1970 MY cars, so someone swapped the trannys...Lucky boy...

Thanks, Jeff! I'm a bit embarrassed that I didn't even think of looking on your site(s) for the Magic Transmission Decoder Ring!!

--DD

All I was trying to confirm was that it was at least a 1973 and it appears that it is. I like this site..................thanks guys.

Seller just confirmed the tranny number is HA 23 02 3

Thanks Jeff and Dave,
What's strange about this trans is that it follows the date code range that Dave talked about. HB 22053 being built May 22 1973. It is a side shifter and I pulled the side cover and it definitely is a LSD. I was wondering if you could special order a LSD in 1974. I bought this 1974 2.0 parts car a few years ago for the 2.0 engine which I sold anyway. I only had the tranny left so I decided to clean it up and that's when I discovered it was a LSD. So it looks like it may be a 1973 LSD side shifter tranny. In any case it is a lucky find.
Thanks,
Jack

The site going down interupted my reply. Yes it is an LSD tranny, and the HB tranny was available all years I believe. M220 was the option.
That was a May 1973 production tranny. It must have been a very early 1974 to get that tranny from the factory I would think.
Is that tranny for sale?

Thanks Dave for the information. No I am not selling the tranny. It will probably go into my son 914 that has a 2.7S engine. We need to keep the back tires planted and this should do the trick.
Jack

In case it'll help anyone in the future, I found an error on the above page regarding engine ID for the 1971 914-6. The 3rd series of engine IDs is listed as:

• 641 4001- 641 0163

...which I've determined should actually be:

• 641 4001- 641 4163

Not nitpicking, this just had me confused and it took me a while (and a couple of other resources) to track down the correct value. Maybe I can save someone else the hassle.

BTW, thanks for the link Dave! The other info on the page was very helpful.