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10-09-2021, 07:39 AM
(This post was last modified: 10-12-2021, 12:13 PM by JonE.)
We talked about this a while ago but I've just noticed that with one of mine, it has 1A part numbers (post '27?) which dates it later perhaps than the 23xxx number stamped in the middle top of the beam. I had presumed it to be chassis number but it could perhaps be stamped as a replacement going to a particular car at the factory.
What beam stamps do people know of and what part numbers are present - can we establish a better pattern?
COULD PEOPLE WITH 3 SPEED BOX TOPS RECORD THE BOX TOP NUMBER AND THE SHIFT PATTERN; IF YOU HAVE A POSSIBLY ORIGINAL GEARBOX, THEN ALSO CHECK PARAZINE'S HYPOTHESIS AGAINST YOUR CHASSIS NUMBER
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Location: North Wiltshire
Car type: 1927 Chummy, 1926 Top Hat 1938 Big Seven 1/2 a Trials Chummy
1A numbers were starting to be phased in during late 1926, there are a few 1A parts on my Top Hat project although most are still XL and this has a production date of mid December '26. The change was very slow, by the time my Chummy was produced in October '27, the opposite is true, i.e. most parts are 1A and a few are XL.
It's possible that numbers of individual parts (e.g. front axle, cylinder block etc.) were issued sequentially from a major change, so yours might be the 23xxxth axle of the type with shock absorber mountings for example.
I'm working on a theory for 3 speed gearbox numbers, I think they can be dated pretty accurately.
Joined: Aug 2017 Posts: 858 Threads: 47
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Location: North Wiltshire
Car type: 1927 Chummy, 1926 Top Hat 1938 Big Seven 1/2 a Trials Chummy
More likely an inspector's stamp I think. I've just checked three gearboxes I can get at easily, a coupled one (1932) has "( )", an uncoupled one (1929) has "O" and the Top Hat (1926) has nothing.
Regarding the numbering on gearboxes, I think that the letter is the first digit, where A=1, B=2, C=3 and so on. The rest of the number is numeric. So the 1926 Top Hat has an original gearbox 8363B, which translates to 28363, which ties in well with chassis 27983, engine number 27998.
My RK saloon has gearbox number 8473I, which becomes 98473, which goes well with chassis 97927, engine 97788.
I have a 1932 RN saloon gearbox in the garage at the moment, it carries 4202O, which translates to 154202, which would make it one of the last three speed boxes.
I'll go and put my anorak back on......
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that's a nice thing for others with original cars to test easily. My only thought is, why would they complicate if it doesnt save work process time? (it actually increases it)
Perhaps so that if the gearbox moved around in later use it wouldn't be noticed?
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BOX TOPS...
4095M would thus be 134095, and the top is a "reverse" pattern (i.e. from modern pattern).
Can we work out the chassis breaks for the patterns, as this would allow the hypothesis to be tested. Especially as the tops have both stamp AND the pattern displayed.
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Location: Sherwood Forest
Car type: 1938 Talbot Ten Airline
I believe the gear-change positions were altered to what would now be regarded the 'conventional' positions, ie 1st is bottom left, with the introduction of the ball-change lever at 99001; the gear positions reverted to the earlier layout with 1st bottom right at 113068. 134095 would therefore be to the latter pattern, ie 'conventional Austin Seven'.
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so the hypothesis currently works!
I've altered the first post to encourage others to contribute.
So to clarify:
to 99000........................................... top position markings will read 2 R (top line) then 3 1 below
99001-113067.................................... top will read R 2 then 1 3 below
113068 till end of 3 speed production...top position markings will read 2 R (top line) then 3 1 below
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Location: Sherwood Forest
Car type: 1938 Talbot Ten Airline
Yes, that's my understanding.
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some more... boxes not tops.
1297 and an O on the corner, miles away. (So could be no letter). Could thus be 151217 but is that too late for a 3 speed?
7213, no letters anywhere. handbrake screw in. But 1A part number so not early. 1A 3100 type change levers
F then big gap then 1842; no handbrake screw in so late. Thus F couldnt work.
As these dont have the tops, then its difficult to tell whether they are stamped with less detail than their original tops.
The 1A 3100 change levers - resembles an 'L' on the left hand side of the box. does this result in the non-modern, "conventional Austin 7" change?
