The Truetrac differential (with its bearing races in place) is then set into the rearend housing journals. It should be a relatively snug fit. Once in place it's time to check backlash. Again, as a rule of thumb, most gearsets are developed to run at about .008- to .012-inch backlash for street gears. Adjustments for backlash are provided by shim packs behind the bearing cups. When the backlash is within specification the bearing caps are installed (pay attention as there is a definite left and right cap) and torqued to the proper rate.