After an a recall early in 2013, involving high oil pressure levels in the transmissions of certain 2013 BMW R1200GS models, BMW was forced to install an oil restrictor to reduce oil pressure at the transmission output.
At the time, BMW was concerned about the high oil pressures in the transmission causing the rear sealing ring to come unseated and leak oil onto the rear tire.
After plugging that leak before any of the bikes managed to reach dealers, and despite installing the oil restrictor, the issue has resurfaced, this time leading to a non-serious accident in Italy, in March of this year.
After engineering analyses were completed last month, BMW determined that the oil restrictor was not sufficient enough to keep oil pressure levels in the transmission from pushing the sealing ring out of place and keeping oil off the rear tire.