David Ty Cae
Registered user
The bevel is in the detail
As mentioned above, I would like to share 2 stories relating to the bevel drive on my R100GS which I am at present restoring - apologies for the slight delay but I have been checking the valve clearances on my S10, which incidentally were within acceptable tolerances.
My first account relates to a leaking pinion seal. This problem was apparent soon after I purchased the bike and you will see from the photos of the castle nut below that it is clear that during the bikes lifetime someone had had a go at removing the nut albeit with a hammer and chisel judging by the mess.
With one side of the nut missing, I regret that my homemade tool was inadequate to remove the nut due to its high torque and I was forced to bite the bullet and try to locate the correct tool - which I managed to purchase from BMW Bayer. Thankfully, with heat, the correct tool was up to the job of removing the nut even though it was damaged.
I uploaded a photo which shows my homemade jig so I could hold the bevel drive in a bench vice, my homemade extractor, the damaged castle nut and the real deal tool which I bought -yes it's the professional looking shiny one!
My second story relates to a clunk which I heard when travelling at 70mph - the sort of mechanical clunk that you know will not sort itself out. I wasn't sure where it came from but I managed to limp home and notice that the rear wheel would not rotate backwards. I thought this could be a drive shaft or gearbox issue or perhaps the bevel. Unfortunately I started from the wrong end and the gearbox seemed fine. I did notice some grooves had been cut into the drive shaft and when I got around to removing the bevel box I noted that the aftermarket "upgrade" bearing substitute I bought had failed (the part is not a bearing, instead it is a pin which can rotate in a greased cup) - the part which failed was the cup/ grease baffle and its part had jammed in between the driveshaft and bevel housing. Needless to say I feel rather fortunate that the wheel did not lock up when I was doing 70mph.
These episodes have taught me at least 2 things :
1. Always use the right tool (there is seldom opportunity to use am hammer and chisel together when undertaking bike maintenance)
2. Whilst BMW swing arm to bevel box bearings are prone to failure after a couple of years, having to replace them is a lot better than an after market part breaking.
I have also uploaded a photo showing the broken cup and the resultant scores to my drive shaft.
In terms of progress on the restoration, I regret to say that the S10 has taken a lot longer than I thought - mainly due to the difficulty in removing the cylinder head through the frame - anyone who has done this job will I am sure empathise. I have however been in touch with RM and am expecting a new camshaft with slightly increased lobes (nothing too crazy) in the next few days.
Thank you for reading and as ever don't rely on anything I say -obtain your own professional advice and oh yes, this post is for entertainment purposes only ( I think that deals with disclaimers)
As mentioned above, I would like to share 2 stories relating to the bevel drive on my R100GS which I am at present restoring - apologies for the slight delay but I have been checking the valve clearances on my S10, which incidentally were within acceptable tolerances.
My first account relates to a leaking pinion seal. This problem was apparent soon after I purchased the bike and you will see from the photos of the castle nut below that it is clear that during the bikes lifetime someone had had a go at removing the nut albeit with a hammer and chisel judging by the mess.
With one side of the nut missing, I regret that my homemade tool was inadequate to remove the nut due to its high torque and I was forced to bite the bullet and try to locate the correct tool - which I managed to purchase from BMW Bayer. Thankfully, with heat, the correct tool was up to the job of removing the nut even though it was damaged.
I uploaded a photo which shows my homemade jig so I could hold the bevel drive in a bench vice, my homemade extractor, the damaged castle nut and the real deal tool which I bought -yes it's the professional looking shiny one!
My second story relates to a clunk which I heard when travelling at 70mph - the sort of mechanical clunk that you know will not sort itself out. I wasn't sure where it came from but I managed to limp home and notice that the rear wheel would not rotate backwards. I thought this could be a drive shaft or gearbox issue or perhaps the bevel. Unfortunately I started from the wrong end and the gearbox seemed fine. I did notice some grooves had been cut into the drive shaft and when I got around to removing the bevel box I noted that the aftermarket "upgrade" bearing substitute I bought had failed (the part is not a bearing, instead it is a pin which can rotate in a greased cup) - the part which failed was the cup/ grease baffle and its part had jammed in between the driveshaft and bevel housing. Needless to say I feel rather fortunate that the wheel did not lock up when I was doing 70mph.
These episodes have taught me at least 2 things :
1. Always use the right tool (there is seldom opportunity to use am hammer and chisel together when undertaking bike maintenance)
2. Whilst BMW swing arm to bevel box bearings are prone to failure after a couple of years, having to replace them is a lot better than an after market part breaking.
I have also uploaded a photo showing the broken cup and the resultant scores to my drive shaft.
In terms of progress on the restoration, I regret to say that the S10 has taken a lot longer than I thought - mainly due to the difficulty in removing the cylinder head through the frame - anyone who has done this job will I am sure empathise. I have however been in touch with RM and am expecting a new camshaft with slightly increased lobes (nothing too crazy) in the next few days.
Thank you for reading and as ever don't rely on anything I say -obtain your own professional advice and oh yes, this post is for entertainment purposes only ( I think that deals with disclaimers)
