With 328K miles of experience the problem as I see it: The gear teeth are prone to fairly accelerated wear and develop slop/notchiness because BMW (Brembo) chose aluminum and probably should've used steel (or something harder than aluminum) for the gear portion IMO. The cost of the parts which then need replaced to eliminate the excess play add up to about $150, more if it's a heated grip. Over the miles I've lubed this area with everything from synthetic bicycle injection grease to plain white lithium and,upon inspection, always found dark aluminum contamination even after just a couple thousand miles --which indicates wear. I just finished up servicing this area and this time I'm going to try something a bit unorthodox unless someone can give a reason why it might be a bad idea (?): a light coat Honda Moly 60. I do realize I won't be able to see any aluminum contamination because of the dark color.

As they come from the factory they have a hefty coating of moly grease and I do agree that a better design could have been used but they learned their lesson (and it only took about 35 years) and changed to a more conventional throttle cable with the 16 Valve bikes.