Right gearbox?

Previously Dave Young wrote:

hi - I have a 1959 Dominator 99 and need to know the correct gearbox for the engine please and the price I would need to pay for the gearbox. Many thanks - Dave

well you need a AMC mk1 gearbox most a stamp marked with a N , or a mk2 as fitted to the Atlas and 650ss

Dave, to add to Anna's advice, your bike would originally have had an 'N****' series serial number box. The later NA series will also fit as will M and (later) MA (Matchless) boxes as they are essentially the same. The later boxes have a better ratio selection for 3rd gear. Commando boxes for RH change bikes will also fit but will need a spacer (1/8" iirc) on the top mounting bolt. As it happens, I have a spare N series box...

Dave - Generally the AMC boxes for Matchless and AJS models are not suitable for your Dominator. Avoid boxes with an M prefix as per the previous contributor's suggestion because the main-shell has the mounting lugs offset so they will not align with Norton engine plates. The engine plates could be modified but then the primary change adjustment will also be problematic. The gear sets will interchange but main-shaft length can also be different. I am not familiar with prefix MA boxes. So stick with Anna's recommendation and look for a prefix N or NA. If you adopt an early Commando box which is a type of NA series you may have to fit a Dominator main-shaft depending on the clutch you use. These message boards are intended to be used as a Technical Message Board for reference and so more care needs to be taken by readers and contributors so that incorrect advise is not included nor heeded. If Mr Arthur will edit his input I shall be pleased to remove my input. Regards, Howard

Agreed, the Matchless gearbox will not fit. Also, Anna already said it should be stamped N, which is correct.

Howard is quite correct; apologies for the incomplete info, I should wait till I am awake before hitting the keyboard.

Dave, could you pm me and I will call to describe the box I have available. It is currently stripped so photos are not a problem, but you may be aware that gear condition etc is very difficult to photograph without it being potentially misleading.