AJS & Matchless Owners Club

G'day, could someone please tell me what size box spanner / socket I need to fit the nut which secures the final drive sprocket on a CP gear box? The nut part number is 176-X-1. The next question is would anyone know what metric equivalent socket would fit? It looks about 42mm across the flats, as I doubt if I can find the imperial box spanner for sale here in Australia. Thanks.

Dunno the actual size (guessing 1" WW or 1 1/8" BSF if close to 42mm AF) but this chart is useful to compare series. 1 5/8" AF might also answer.
http://www.baconsdozen.co.uk/tools/conv ... charts.htm

I use a large adjustable spanner but perhaps they only come in metric sizes in Australia!

Thanks for the replies. The chart is very useful. I was using an adjustable spanner, but because of the dished shape of the sprocket it is not easy to get good purchase on it, especially with the chain fitted to stop the sprocket turning.

i remember i purchased a 42mm socket hex socket ( not bi hex) , its a bit tight so go for a cheap make as its more likely to be sloppy
it actually measures 42.47mm across flats

One inch whitworth

Yes, a 42mm deep socket did the job, I found a relatively cheap one. I was unable to find any 1" Whitworth box spanners or sockets.