43-tooth large bevel gear for center differential is machined from special HUDY steel material which has been specially developed for gear-type products, additionally hardened and precision ground to fit the tightest tolerance requirements for perfect fit with the diff outdrives. The gears are individually machined on a precision German gear machine and every gear is individually tested, inspected, and run in. The diff gear is then laser engraved with "Active 43T" for easy and instant recognition.