 25 With the front differential...  25 With the front differential on the work bench, Brusman and Hustead dismantled it. |  26) The AAM 925 IFS axle...  26) The AAM 925 IFS axle is made out of aluminum, but features a cast-iron extension housing on the passenger side so that both halfshafts are the same length. The central-axle disconnect shifter and coupler are also partially housed in this piece. |  27) To access the gears in...  27) To access the gears in the AAM 925, the two case halves were split open on the bench. Here you can see the 91/4-inch diameter ring gear and differential. |
 28) Then the front driveshaft...  28) Then the front driveshaft yoke was removed from the pinion using a puller. The pinion was then pressed out of the housing. |  29) The new 4.56 pinion gear...  29) The new 4.56 pinion gear was installed with new bearings, a crush sleeve, and an old pinion shim back into the housing. |  30) Just as with the rear...  30) Just as with the rear gears, the pinion bearing preload was set by torquing the new pinion nut. Again, the preload was verified by measuring the drag on the pinion gear with a torque meter. |
 31) Brusman then removed...  31) Brusman then removed the stock 3.73-ring gear from the carrier assembly. |  32) Hustead cleaned the carrier...  32) Hustead cleaned the carrier and installed the new Yukon 4.56-ring gear onto it using a vice to hold the carrier so he could torque the bolts. |  33) The carrier assembly...  33) The carrier assembly was then installed back into the differential housing. |
 34) Checking the gear pattern...  34) Checking the gear pattern was a bit tricky on the front, as it had to be done through a port in the housing. But the same principals were used to check the backlash between the pinion and ring gear. |  35) Once Brusman was satisfied...  35) Once Brusman was satisfied with the pattern of the gears, the AAM 925 axle was assembled using anaerobic sealant on the surfaces. The differential was now ready to be installed back into the truck. Hustead used a transmission jack again to lift the differential into position and bolt it into place. |  36) The halfshafts were bolted...  36) The halfshafts were bolted to the differential, the driveshaft was installed, and the differential was filled with Royal Purple gear lube. |