hi all, think i made a mistake on gearbox swop, i have a b40 wd and it has the military gear ratios, so i thought i could put a c15 road cluster in place, the gearbox i got must be from 1960 to 64,on inspection the main shaft was shorter, and the lay shaft diameter is slightly smaller, i tried to fit it into the kick start ratchet which has the later needle bearing and is rather sloppy, i then thought i could swop the gear cogs from the road c15 onto the wd shafts but these gear cogs did not go onto the shaft they were to small in diameter to go on, so i guess the c15 box gets stored and i look for a later b40/c15 road cluster after 1965, so any thoughts or info on this would be appreciated .
Basically, it comes down to using a gearbox from a side points engine - up to 1965 both the C15 and B40 used a distributor and the engines still bore a close relationship to the original Tiger Cub engine they were derived from. With the change from distributor to side points, the inner timing cover completely changed as did the kickstart mechanism. Designed in 1967, the B40WD incorporated these changes.
I looked previously at what I would need to change on my b40WD gearbox to make it standard B40. I'll dig out the info and let you have it tomorrow.
Reading Rupert Ratio, it looks as though there were 3 x gearbox cluster types fitted to the C15 and B40. There is the pre-1965, Tiger Cub type that definitely won't fit a B40WD; there is the transitional type introduced when the change was made from distributor to side points in 1965; and there is the later type that was fitted to the end-fed engines from about 1967 and also fitted to the pre-OIF B25 and B44.
The transitional gear clusters may well fit a B40WD but it is probably safer to fit one from an end-fed engine or from a pre-OIF B25 or B44. The B40WD is fitted with this type of gear cluster and uses the same mainshaft and layshaft.
thanks for looking up the info, i now know where i went wrong and what to look for, i hope to find a cluster before the spring so i can get up and running, if not i may have to start on a 52 golden flash plunger that wants putting back together.