25-08-2018, 01:43 PM
David
You might want to look at the Austin 7 clubs association archives site which has the spares books with pictures and parts numbers for the various years. There is also the cards containing notes on the changes introduced to the 7 over the years.
Include in your viewing the Big 7 spares list.
However when comparing drum part numbers you may be introduced to a little confusion?!?! you will see what I mean. My quick look has.
From my knowledge the drums with locating dowels were up to around 1937/8. This was a patent so that wheels with slots and dowel locating holes could be removed without fully taking off the 3 nuts by just loosening them then twisting the wheel so the nuts passed through the dowel locating holes. Later, cast drums reverted to having no locating dowels and had wheels with no slots and no dowel locating holes, just the normal tapered hoes for the wheel nuts .
Be aware that 38/39 (and late 37?) hubs for both 7 and Big 7 had larger outer diameter bearings and thus diameter hub central part so the drums had enlarged central holes ......not certain whether any of the later large hole drums had dowels or not.
The front hubs on later 7s were also enlarged to take the larger bearing (the inner one) for ease of continuity/servicing between these later rear ("heavy") axles and front axles. Big 7 and 7 hubs and drums are interchangeable within the above bearing limitations......earlier cast drums can be fitted to large bearing hubs by just opening out the central hole.
Best to only use wheels with no slots on the no dowel drums.
There is someone supplying a better design wheel nut and washer combination.
Dennis
You might want to look at the Austin 7 clubs association archives site which has the spares books with pictures and parts numbers for the various years. There is also the cards containing notes on the changes introduced to the 7 over the years.
Include in your viewing the Big 7 spares list.
However when comparing drum part numbers you may be introduced to a little confusion?!?! you will see what I mean. My quick look has.
From my knowledge the drums with locating dowels were up to around 1937/8. This was a patent so that wheels with slots and dowel locating holes could be removed without fully taking off the 3 nuts by just loosening them then twisting the wheel so the nuts passed through the dowel locating holes. Later, cast drums reverted to having no locating dowels and had wheels with no slots and no dowel locating holes, just the normal tapered hoes for the wheel nuts .
Be aware that 38/39 (and late 37?) hubs for both 7 and Big 7 had larger outer diameter bearings and thus diameter hub central part so the drums had enlarged central holes ......not certain whether any of the later large hole drums had dowels or not.
The front hubs on later 7s were also enlarged to take the larger bearing (the inner one) for ease of continuity/servicing between these later rear ("heavy") axles and front axles. Big 7 and 7 hubs and drums are interchangeable within the above bearing limitations......earlier cast drums can be fitted to large bearing hubs by just opening out the central hole.
Best to only use wheels with no slots on the no dowel drums.
There is someone supplying a better design wheel nut and washer combination.
Dennis