To service and repair the carrier bearings remove the j 42168-9 and the thumbscrew from the j 42168-1 then remove the j 42168-1 from the bore of the Differential housing on the left bearing cup making sure the tool is level to take accurate measurements. Attach the dt-48009-2 to a vice, then fit the bearing cup to it and set the Differential case in place over the bearing cup, turning the Differential to locate the bearing with the race. Place dt-48009-3 in the j 42168-2 hole, back out the thumbscrew enough to get the rod touching the bottom of the bearing race hole, reinstall the dt-48009-3 and tighten the thumbscrew and remove the dt-48009-3 from j 42168-2. Cinch the dt-48009-3 to the ring gear side of the Differential using a ring gear bolt and rotate Differential until the rod is above the dt-48009-2 gage block, use upper gage block location for 2.56 Differential ratio or lower for 3.42 ratio differentials. Measure the distance between the rod of the dt-48009-3 and gage block and record as dimension c1, then subtract c1 from a nominal value of 5 mm and get c2. Find the a2 value on the side of the ring gear, keep in mind that it is not the same for a2 value 65.5 mm for 3.42 ratio differentials or 74.5 mm for 2.56 ratio differentials. Subtract the d nominal value from a2 to determine c3 and add c2 and c3 for the left side Differential Bearing shim thickness to pick shims equal to this computed value. Loosen pinion housing-cage bolts and remove pinion housing-cage from Differential and then remove j 42168-11, bearings, sparer and j 42168-2 from pinion housing-cage with the help of dt-48008 to support Differential housing in press. Apply the shim and bearing race selected to the Differential housing with the aid of the dt-48008, j 42170 and a hydraulic press and then fit the ring gear to the Differential with proper alignment against several bolts, or with the help of hammering and a brass punch if needed. Insert new ring gear bolts and tighten to 195 n.m for first design or 145 n.m for second design bolts, and install Differential assembly onto j 42173 and the j 42155 to place Differential case into housing. Fit the right side bearing cup and j 42168 15 to the Differential with oil seal taken out of right cover and the pinion housing-cage not fitted. Install correct cover and j 42168-16 bolts and spacers and tighten to 30 n.m, then measure the gap with a feeler gage to find the right side Differential Bearing shim size. Loose the bolts, cover and tool and install the chosen shim and bearing cup in the right cover with the j 42170 and hydraulic press.