I suspect that MMC have done the same deal with Treven that they seem to do with most of their suppliers for bespoke parts where it is not possible to get the parts from anyone other than MMC. This is the same with Quaife for the Bevel Box and steering rack, Spax with the shock absorbers, TTV with the clutch, Centa with the compensator, the list goes on. It may be why they stopped using the far more reliable Lifeline item, as it was an off the shelf product that they couldn't stop being marketed. Traven make the steering racks for the 4 wheelers, I wonder if they have the same parts supply limitations?
