In around 80,000 miles of use I have gone through 3 drive sprockets (PR50-22A) on the Burman gearbox fitted to my Comet. What fails is the splines on the inside of the sprocket that engage with the gearbox drive shaft. Fortunately its the 'steps' on the inside of the sprocket that wear away and not the splines on the drive shaft itself. First time I experienced this I was stuck on the side of the road having lost all drive. On disassembly the inside of the drive sprocket looked like it had been machined - perfectly smooth with not a trace left of the engagement splines!
Its less than 1,000 miles since I last replaced the sprocket, including fitting a brand new PR50-17 -1BA lock washer but again I find there is discernible 'play' with movement of the sprocker relative to the drive shaft.
Is there some 'secret burman business' to getting this area secure so that it the retaining nut PR50-218X does not work its way loose ?
Its less than 1,000 miles since I last replaced the sprocket, including fitting a brand new PR50-17 -1BA lock washer but again I find there is discernible 'play' with movement of the sprocker relative to the drive shaft.
Is there some 'secret burman business' to getting this area secure so that it the retaining nut PR50-218X does not work its way loose ?