I refreshed this box two years ago, and it’s back for another look. When I pulled it apart, the crown wheel (ring gear to us Americans) and pinion were badly worn. It’s been a challenge finding technical information, as Quaife has nothing other than an exploded diagram, and Radical has moved on to the slight bigger Q72 for the latest SR8s. Still, after a lot of searching I’ve found that the pinion depth should be 109.9mm, the differential bearing preload should be 12-15 Nm, and the backlash should be between .004-.008 inches. I’ve worked out how to measure and set up the pinion depth, and I’m working on the preload and backlash set up now.
I made the following video about pinion depth and how to measure it in the gearbox:
I’ll be posting more videos about the rest of the gearbox refresh process.