High Performance Bearing Kit for BMW Differential 215k 215l 215lw

For customers with highly modified cars, or who use their cars aggressively, or for those with high mileage cars looking to prolong the life of their differentials, we would recommend our high-performance bearings.

These uprated tapered bearings offer a 44% increase in load capacity compared to the standard BMW ball bearings, providing much improved durability and a longer lifespan.

BMW have seen fit for many years not to provide support for repairs to BMW final drives. You only have to look at the parts catalogue to see that they prefer to sell a complete final drive, rather than offer parts for repair purposes. There are many reasons why they have done this, but we believe the principal one is that they do not equip BMW dealers with the necessary skills and knowledge to repair any of BMWs "major units". For those of us who have the skills to repair, this is a major annoyance and costly inconvenience.

Of course those in the know recognise many of the required parts which, once identified, can be purchased either from BMW or form proprietary parts suppliers. In the case of bearings, however, BMW have equipped many of the later model cars with bearings that are absolutely not available from any supplier. Luckily, Birds have the resources to generate the solution.


We have recently commissioned a bearing manufacturer to provide not only a direct replacement bearing set, but have taken the opportunity to increase the bearing ultimate load capacity by a full 44%. These bearings are fully guaranteed against failure for 36 months, irrespective of the load. Owners of very high output 135i, 335i, 335d vehicles can now increase the duty of the weak low friction side differential bearings, usually in conjunction with the world leading Quaife ATB limited slip differential conversion.

Birds offer replacement pinion bearings for 215l and 215k final drives. Both front and rear pinion bearings are deisgned to dramatically increase the load carrying capacity for prolonged life of the bearings. Please note that the installation of pinion bearings is a technically complex job and, as a consequence, we only recommend installation by a competent expert who understands the practice. We regreat we cannot offer technical support for work of this nature.

 The critical bearing is the large bearing (item 7). This bearing carries the vast proportion of the load. It has to be perfectly alinged with the crownwheel and requires specialised knowledge to set it correctly. The shim (item 6) controls the pinion penetration into the crownwheel. Assuming that the original crownwheel and pinion are being re-used, then the total height of the shim, the bearing spacer provided and the bearing itself should be identical to the original height. If not, the shim or spacer will require grinding or, in exceptional cases, additional shims added to gain the correct bearing stack height. This method removes the need for long-winded installation, measurement, removal and correction.


Below are pictures of both types of bearings. On the left are the standard double-row ball bearings commonly in production. On the right, our own taper roller bearing with a typical load rating 44% higher than the standard double-row ball races.