Norton Gear Identification 1935 - 49
Peter Roydhouse Roadholder No. 136 - Nov/Dec 1987
Details of early gearbox components
Difficulty is often experienced when reassembling gearbox internals where AMC gears or occasionally Sturmey Archer 4 speed components have been intermingled. All the components are visually almost identical.
Detailed examination will reveal that the AMC gears have a different tooth and form and on some gears a different arrangement of dogs. The AMC shaft splines are identical with earlier items, but normally the AMC gears do not have any numbers stamped into them. Sturmey 4 speed gears are identical with the Norton gears and only the numbers stamped into them differentiate their origins.
The basic guide is that Norton gears carry an eight thousand number prefixed by the letter "N" the Sturmey gears carry the prefix "EIV" followed by a number. Both types of gears are stamped with the number of teeth.
The following tables show the major numbered items in upright Norton and 4 speed Sturmey boxes. The gears in the "laid down box" are the same, with the exception of the main axle which is shorter.
NORTON GEARBOX | ||||||
STANDARD | Teeth | CLOSE | Teeth | WIDE | Teeth | |
Gearbox Shell 1935 to 1945 | N8001E | N8001E | N8001E | |||
Gearbox Shell 1945 to 1949 | N8001 | N8001 | N8001 | |||
Gearbox Shell 1949 to 1956 | GT 100 VAF | GT 100 VAF | GT 100 VAF | |||
Main Axle | N8034 | 24 | N8032 | 23 | N 8047 | 25 |
Layshaft Pinion | N8035 | 18 | N8033 | 19 | N8048 | 17 |
Mainshaft Sliding Pinion | N8036 | 22 | N8036 | 22 | N8162 | 21 |
Layshaft Free Pinion | N8037 | 20 | N8037 | 20 | N8163 | 21 |
Mainshaft Free Pinion | N8040 | 18 | N8038 | 20 | N8160 | 16 |
Layshaft Sliding Pinion | N8041 | 24 | N8039 | 22 | N8161 | 26 |
Mainshaft Pinion | N8044 | 13 | N8042 | 14 | N8164 | 12 |
Kickstart Pinion | N8045 | 29 | N8043 | 27 | N8049 | 30 |
Racing Mainshaft Pinion | N8107 | 17 | ||||
Racing Layshaft Lowgear | 25 |
STURMEY-ARCHER GEARBOX | ||
STANDARD | Teeth | |
Gearbox Shell | EIV 130 | |
End Cover (footchange) | EIV 131A | |
Camplate Quadrant Lever | EIV 134A | |
Main Axle | EIV 401 | 24 |
Layshaft Pinion | EIV 30A | 18 |
Mainshaft Sliding Pinion | EIV 6 | 22 |
Layshaft Free Pinion | EIV 10 | 20 |
Mainshaft Free Pinion | EIV 90A | 18 |
Layshaft Sliding Pinion | EIV 91 | 24 |
Mainshaft Pinion | EIV 8B | 13 |
Kickstart Pinion | LS 407C | 29 |
Kickstart Axle | LS 502 |
© Norton Owners Club 1987 & 1996