play on the rear wheel:
A friend of mine had the following problem with his 1978 R100RS. When the bike is on it's centre stand en in gear the rear wheel has half a turn free play between universal joint and rear wheel.
When taking down he noticed that a heavy spring inside the drive shaft housing had broken, not a serious problem but it is disturbing when accelerating.
The replacement of the spring was a tough job because the drive shaft had to be removed from the shaft housing. To do this he had to make a tool to supress the shaft for releasing the lock ring which resides on the shaft, inside the housing (at the wheel side).
The tool consists of two steel plates that are connected to each other with four thread ends. One of the plates must have a pretty big hole in the middle, big enough to leave you space to remove and place the lock ring, small enough to firmly hold on to the end of the drive shaft case.
Because the spring is broken taking down is the easiest job, reassemble the shaft with the new spring is a hard job.
The lock ring is a round, almost closed steel ring with no holes to put a plier in and it resides inside the tube so it's hard to reach. To place the lock ring another tool is needed, it can be made of a piece of axle with the same thickness as the shaft and a little piece of tin plate. Fold the plate around the axle and put the lock ring over the plate. Now you can hold the axle against the shaft so that the tin plate covers both of them and you can push the ring over the plate to it's wanted position.
(c) W.P.Barendsen 2000