What about warranty?

What about warranty?

Current BMW Warranty handbook states:

"Neither the Manufacturer, the selling BMW dealer or any BMW Group in the UK can be held responsible for modifications to the vehicle which lead to defects."

This is a fair and reasonable statement. It clearly follows that any defect that is NOT directly caused by a modification IS covered by their warranty.

We have been directly responsible for the sale and/or installation of over 2,000 Quaife ATB differentials for BMWs worldwide, and not a single one of these has resulted in BMW claiming a fault or defect was a result of the Quaife installation. Moreover, the Quaife carries a LIFETIME manufacturer's warranty. Remarkably few defects have occurred in service, and have all been as a result of faulty installation or physical damage upon installation by others (maybe 4 or 5 instances). 

We cannot speak on behalf of other differential manufacturers, but product reliability is of paramount importance to Birds. We will only offer products that have been fully tested and are guaranteed only to affect BMW ownership and driving pleasure in a truly positive way.