Safety recalls are a common occurrence, but what we don’t often see is the preparation companies go through before issuing their public announcements. A rather large BMW Motorrad service and possible recall program is very nearly underway, according to new reporting from German publication Motorrad. That means BMW is extremely busy behind the scenes, getting its extensive dealer network ready for a worldwide campaign.
What’s the problem? Apparently, some 440,000 bikes need their cardan shafts checked. If they’re found to be damaged, then a remedy service should occur. To be absolutely clear, this isn’t a recall yet. In fact, as of July 15, 2022, it’s an area of special concern that BMW technicians should plan to check at the next service interval—not something that requires riders to drop everything and run to their nearest dealer ASAP.
What’s a cardan shaft? For those not steeped in BMW lore, “the cardan shaft is a secondary drive between the manual gearbox and rear wheel,” according to BMW. Paralever BMWs use it to transfer power while keeping the entire structure lightweight, particularly in terms of its unsprung weight.
From BMW: “The light alloy housing of the rear wheel gearbox is connected via a joint with the single-arm paralever swing arm, which is also cast from light alloy. This wing arm retains the cardan shaft. An additional universal cardan joint at the pivot point of this link transfers power to the rear-wheel transmission, the housing of which is supported on the frame via a leading link. The cardan shaft is likewise connected with the output shaft of the gearbox via a universal joint.”
What BMW motorcycles are believed to be affected? Mainly, GS bikes from 2013 forward, particularly the 2013 R 1250 GS and R 1200 GS and Adventure bikes, as well as RTs. Damage to the cardan shaft, such as corrosion and wear, can impair its function and lead to propulsion loss. So far, bikes from 2013 have shown the greatest incidence of these problems.
As a result, BMW has developed and is instructing its dealer network about how to test bikes to see if they need further service to address cardan shaft wear issues. Since digging into the cardan shaft isn’t something anyone wants to do unless it’s totally necessary, there’s a specific stress test procedure that BMW technicians can run to check whether everything is operating within an acceptable range.
If problems are found, affected cardan shafts will have a vent hole retrofitted, using a predefined template to keep them uniform. Then, a special one-way rubber valve will be installed, which will allow moisture to escape from within the shaft, but not allow any unwanted debris to get into the shaft from the outside.
These tests are expected to add an additional 45 minutes of time to the bike’s next service, and will be performed free of charge to customers. Cardan shaft ventilation is now standard practice on paralever GS models, since October, 2021, but paralever models produced before that time will likely encounter this check in the near future.