The Performance Gearing craftsmen noticed a trend toward "unit replacement" that started in the late '80s. Rather than facilitating the rebuilding of engines, BMW stopped offering repair parts for their differentials (and some transmissions). This forced owners to purchase a new factory unit. However, it was common knowledge within the automotive industry and among BMW enthusiasts that many of the internal components (including ring and pinion gearsets) were interchangeable as far back as 1977. The latest BMW design change put an end to this interchangeability. The introduction of the '95 models came with completely redesigned differentials. These featured unique ring/pinion gearset dimensions -- which meant that any pre-1995 BMW internal components were now not compatible or swappable with those from later models. Not only are ring/pinion ratio options severely limited, but more important, limited slip was deleted from all but the Motorsport models. From 1965 to 1995, limited slip was a highly prized option, valued by high-performance drivers and BMW enthusiasts all around the world. After 1995, it simply was no longer an option... until now.
All Performance Gearing products are race-proven, whether the components are intended for such use or not, to ensure reliability in the most demanding of situations. We feel so confident in our products and their performance capabilities that we offer a three year warranty, with unlimited mileage. We stand behind every single differential we sell...because they're not mass-produced, they're individually crafted.