Gearbox/transmission codes - again!

[Chippy Senior]

(Similar cross-posted on TheSamba)

Hi - sorry to raise this topic again. I have read many prior threads on the subject (here/Samba/STF) and still do not have definitive answers. Several of our UK group members are holding spare autostick transmissions and it is not clear whether they may be suitable/straightforward replacements for their vehicles (if and when the time comes).

Tables/Charts/Lists
A chart/list that is commonly shared looks like this (sometimes with individual gear ratios included):
BA 1300/1500 4.375 Semi Automatic from 8/68 – 8/70
BC 1300/1500 4.375 Semi Automatic from 8/68 – 8/70 with LSD
BE 1600 4.125 Semi Automatic from 8/68 – 8/70
BF 1600 4.125 Semi Automatic from 8/68 – 8/70 with LSD
BG 1300 4.125 Karmann Ghia Semi Automatic from 8/70
BH 1300 4.125 K. Ghia Semi Automatic with LSD
BJ 1300 4.375 Semi Automatic from 8/70
BK 1300 4.375 Semi Automatic from 8/70 with LSD

Some versions of the table have an additional row:
BL 1600cc 4.125 Semi Automatic

And some have a further BK row following BL - not sure if this is an error, or a typo for BM/BN (or something else):
BJ 1300 4.375 Semi Automatic from 8/70
BK 1300 4.375 Semi Automatic from 8/70 with LSD
BL 1600 4.125 Semi Auto
BK 1300 4.375 Semi Automatic from 8/70 with LSD

Or there's another version that has differences for BG code (1600 KG vs 1300 above):
BA 1300 / 1500 4.375 Semi Automatic from 8/68 – 8/70
BC 1300 / 1500 4.375 Semi Automatic from 8/68 – 8/70 with LSD
BE 1600 4.125 Semi Automatic from 8/70 – 8/71
BF 1600 4.125 Semi Automatic from 8/70 – 8/71 with LSD
BG 1600 4.125 Karmann Ghia Semi Automatic from 8/70
BH 1300 4.125 Karmann Ghia Semi Automatic from 8/70 with LSD
BJ 1300 4.375 Semi Automatic from 8/70
BK 1300 4.375 Semi Automatic from 8/70 with LSD
BL 1600 4.125 Semi Auto
BK 1300 4.375 Semi Automatic from 8/70 with LSD

Some form of this list appears on various part supplier websites, typically as part of a longer list including manual 'box codes.

However no-one appears to have questioned why BO doesn't get listed despite many examples in existence? BO would logically come later in the alphabetical series, following BL (or BM/BN, if used). However there's some suggestions that these were early '68 boxes and BO actually came 'first'.

From images I've seen there's a difference bewteen a stamped O and a stamped zero. One has stright sides, the other is rounded. However to confound us all these seem to have been used somewhat interchangeably.

Missing codes...
- What were BB and BD codes reserved for, when we can see sequences BE/BF/BG/BH and BJ/BK/BL were all used? (Note: I assume BI was perhaps not used to avoid confusion with B1?)
- We haven't seen any physical examples or photos of BC/BF/BH or BK - so does anyone know if VW actually made any AS/SA gearboxes with the limited slip diff? (Note: there is a singular old VWAR comment suggesting someone was acquiring a BH, but that could be a typo/error? And there's a couple of Samba comments that suggest no-one's seen a LSD AS/SA gearbox!)

And what's the story with KGs?
- The list specifically calls out KGs (type 14) against BG and BH, so what was fitted to KGs before 08/70? And why were BG and BH specific to KGs? What was different?
- At least one version of this table suggests BG and/or BH were used in 1300 KGs after 08/70 but VW stopped 1300 KGs in '67. Would these 1300s have been 'special orders' or is this an error in the table?

The digits...
- The digits that follow the two-letter code vary in length. We've seen/got 5, 6 and 7 digit examples (shown with spaces as stamped, where known):

BA 021 5573 ('69 beetle)
BA 021 6090
BA0230 438
BA025 2645 ('69 beetle)
BA0 27 3904
BA033 1638 (my '70 beetle)
-
BG 06043
BG04 73244
-
BJ 16073
-
BL 11103
-
BO 004426
BO 011 521
BO 011814
BO 021412 (two temp senders)
BO 051107
BO 075 416
BO077 939 ('68 KG)
BO 089 785
BO 107 848
BO 119 741

- Are all BJs and BLs 5-digit? (Note: there was a theory that this represented manufacture date as dd/mm/y, however this format doesn't hold true for 6- or 7-digit examples... plus it can't carry forward as the first five or last five digits, those ideas don't work either).
- Are all BOs 6-digit?
- Are all BAs 7-digit? Or was it a BAO code with 6-digit?
- What's going on with the BG examples above?
- Any clarity on the changing numerical format between the letter codes?

Other details...
- I've never seen a list that further correlates the two-letter codes to other details such as casing design; front & rear mount type; number of temp sensors; number of drain plugs; park function; reverse light switch etc - all of which vary.
- Or maybe there is no direct correlation and the (serial?) number is registered back in the archives against these other parameters/specifics?
- No service/technical manual that we've found goes into this level of detail either. (Note: there is a past VWAR comment suggesting that 'a couple' of someone's 'books' listed the codes, but no further details unfortunately).

So... does anyone out there have access to a more definitive; correct and fuller history of AS/SA gearbox codes? I'm hoping (dreaming?) that this kind of info isn't lost for good!

(I've written to the Stiftung AutoMuseum Volkswagen but don't expect a detailed response. Next stop will be the VW corporate archives...)

Cheers, Chippy Senior
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