Dolls head gearbox

That number makes no sense in the context of the pre-war factory records and any shell that I've seen. The post-war upright shells are interchangeable though so that may be a possibility. 

A photo of all the stampings would be really helpful.

The VMCC "Register of Machines" (no longer published I believe) lists numbers like that for post war gearboxes.  A box numbered G56AZ58 is listed for a 500ohv Norton from 1951.

Lots of prewar boxes have SN numbers...like SN24902.

G numbers seen to start after the war.

I can't see any logic!

I have a few pages copied from the 1946 factory records and they don't show gearbox numbers, simply a letter. Sometimes 'G' but also 'M' , 'K' and 'A46' It makes no sense to me, unless they were using the column for something else.

Pre-war (and WD16H) gearbox numbers always seem to be stamped 'SN' which I assume simply indicates 'Serial Number'. It's not referenced in the factory records.

Does this box have the ratios stamped across the top ?

Hi Simon/Richard,

   Just a guess, is this from a 500T trials possibly 1951 ? These were much the same as the W.D. sideccar gearbox but had a much shorter kick-start axle and casing for competion use and were fitted until 1954.

Simon, can you load any full view photos of gearbox which might help with identification.

Richard, I have a few upright gearboxes with the SN stamping and a couple of Inter ones with IN stampings. My thoughts are the SN stands for Standard Norton and the IN stands for International Norton. I will have to look at a couple of Brough Superiors when I get to a large bike event to see what serial numbers/letters they have.

Richard. You could be on to something there. I've had a word with a friend who has several wide-ratio boxes for SWD Big 4s and they are marked "TNS" - "Trials Non-Standard" perhaps ? The pre-war factory records only show the numerics and not the prefixes. In the usual Norton way, they're not consecutive, but they more or less follow on as a single series.

None of this of course helps with identifying post-war shells !

The cover on the positive stop change is prewar.  Richard will tell you the date they added the brass indicator plate.  

The box has no gear ratio numbers on the back of the case.  I think that makes it post war when I understand that the ratios were only stamped on non standard boxes (trials, Inters etc).

It's easy to get inside.  Then you can count teeth and work out ratios.

Hi Simon/all,

   As David says, the pre-war and early WD boxes didn't have the brass indicator plate. This was fitted to aid dispatch riders who might not be fully experienced with Nortons and also when in difficult combat situations. Ex competion riders were used to train dispatch riders and would recommend this sort of mod to make for easier use. I would guess this would have been done sometime in 1940.

   This gearbox looks to have been used in a competition machine with the kick-start being cut off and may have been built from a mixture of various parts from different years as most of these parts are inter-changeable. I agree with David, it will be interesting to see what's inside.

Whether a CR box is a good thing depends entirely on what you're going to use it for. Pretty hopeless in a 500T !

Hi my gearbox number is G56A219 and its on a 1950 500t 

Hi.

Here's some info from Ken MacIntosh that appeared on F.B. a while back, it's regarding a Manx gearbox, but I hope may be of use. Cheers. Ian.

The ratios are sometimes stamped on the back face of the main shell.

I do not have G55 on my list but I think it will be correct for a Daytona (USA) spec Manx.

G56 is 500T trials. Here is my list with G55 added! There may be a different code for the later Daytona g/box with the 2.0 : 1 first gear ratio.

The "G" numbers are from Burman who made the g/boxes under contract to Norton.

Burman use G prefix on their own gearboxes used in Vincent, AJS, Matchless, Panther and lots more.

Post-war "Dolls-head" gearbox numbers

Prefix Model Year

G5 16H, Big-4, ES2 1946-49

G15 International, “Garden-gate" 1946-52

G16 Manx, "Garden-gate" 1946-50

G55 Daytona Manx

G56 500T 1949-54

G110 500T

Post-war "Lay-down" gearbox numbers

Prefix Model Year

G82 Model 7 with plunger frame 1949-51

G101 Side valve & OHV singles with plunger frame 1950-52

G102 Model 7, side-valve & OHV with swing-arm frame 1952-56

GB8 Model 88 & 99 with featherbed frame 1952-56

GB21 International with featherbed frame 1953-57

GB9 Manx with featherbed frame 1951-57

G18 Daytona Dominator 88 using Inter close ratios with K/start and Daytona Manx 1st gear. Only 8 made. 1957