GM 25978167
Carrier Assembly, Front

Clean and examine the differential case using solvent and check for chips, cracks, bolt hole damage, usual wear, groove wear, scoring wear, any defective side bearing flanges, heat discoloration, and worn differential pinbores. Clean the pinion gear in solvent and look for peculiar wear of gear teeth, pitting, heat discoloration , wear, pitting, or twisted slink splines on the pinion splines, condition ofpinion shaft threads, and see if the pinion gear end is not bent or burred over . Use solvent to clean the ring gear, then check it for the damage of threaded holes and unusual wear or heat discolored teeth of the gear. Clean the pinion flange in solvent and inspect wear, pitting on the splines, or twisting in groove and pitting on the sealing surface. Visual examination of the bearing rollers and races for such defects as pitting, scoring, and grooves, excessive wear; look for the heat discoloration, which can be from faint yellow to a dark blue, indicating possible overload or improper lubrication; Any bearings or races which are showing color due to heat must be changed out. Also, check for bent bearing cages and bearing cages' damage.

Clean the differential case in the solvent and note chips, cracks, injury to bolt holes, rough wear, grooves, scoring, damaged side bearing flanges, heat discoloration, badly-worn differential pin bores. Also clean the ring gear in solvent and check for any damage to the threaded holes and any abnormal wear or heat discoloration of the gear teeth. Use the pinion flange to clean it with solvent, and make inspections for wear, pitting, and splines and grooves or pitting on sealing surface. Examine the bearing rollers and races for pitting, scoring, grooving, extreme wear, and other defect, with heat discoloration that varies from pale yellow to deep blue, which imply overload or insufficient oil; Any heated colored bearings or races must be changed. Further, check for bent bearing cage, and inspect for damaged bearing cage.

To service and repair the Differential case you first make sure that safety persons are used. Clean the Differential case in the solvent to check for chips, craks, bolt hole damage , unusual wear, grooves, scoring, damaged side bearing flanges, heat discoloration, wheard Differential pin bores. Additionally, inspect the gear for corrosion, heat discoloration, unusual wear or scoring in positions of the Differential pin bore, wear and coat removal, as well as scorings on Differential s pin side gear washers, scattering, and unusual wear in side gear splines on axle. Clean the pinion flange in the solvent and inspect for wear, pitting, or twisting of the splines and grooves or pitting on the sealing surface. Examine the bearing rollers and races for pitting, scoring, groove, excessive wear and heat discoloration which could be an indication of overload and improper lubrication; kip any parts that have been discoloured with heat. Check the damaged bearing cages , also clean the Differential carrier in solvent , check pinion housing bolt hole threads , also check carrier cover bolt hole threads , carrier cover sealing area , drain plug threads , and axle seal area , respectively. Clean oil passage between and in axle bearing cup bore so that surfaces are free and clean from nicks and burrs. The Differential Cover is then cleaned in solvent and examined for flow of oil between and in the axle cup bore, fill plug threads , o-ring groove, and cup and shim surfaces. Inspect the cover axle seal mounting surface and clean the pinion bearing housing in solvent and keep it air dry by blowing the oil from the holes behind the cups. Make sure that there are no nicks, burrs on the mating surface to prevent binding or clean the o-ring groove. Use the housing only if old bearings are being used, and newensions and spacer are actually a kit with it being pre-cut and not for field service.

To put this Differential carrier together, first use bearing grease to secure the gear and washer in the Differential carrier, followed by lateral axle side gears (107) and washers (106). Then, put in the washers (108) on the pinion gears (109) and put the pinion in the Differential carrier (104) next to each other and across from each other aligning the center Differential shaft (103). Slowly rotate the gear will be aligned then insert the Differential shaft (103) and the matched hole in Differential case (104) and pinion gears (109). Install the bolts with the heads uninstalled to guide into the gear bolt holes and not press too much on to the Differential causing the damage to the gear teeth. Then use a press and the pin ion cone and side bearing installer (J 24 433) to press the ring gear (105) on to the Differential. Replace the guide pin with new ring gear bolts and tighten them to 67 nm (49 ft. Lbs) in criss-cross-pattern. Two different types of bearings fish in place on the drive pinion shaft (111) using the pinion cone and side bearing installer (J 24433) and a hydraulic press, are it's the pinion head bearing onto the drive pinion gear (111), thus, assemble the drive pinion shaft (111) and pinion bearing spacer through the pinion bearing housing with tail bearing over the pinion shaft to press the bearing onto the pinion shaft, with the pinion cone and side bearing installer (J 24433) and a hydraulic press. Install a new pinion seal with the help of pinion sealer (J 46262), and put the pinion flange on the shaft and a new pinion nut . With the use of the pinion flange holder (J 45012), hold the flange with a breaker bar and tighten the pinion flange nut to 241 nm (178 ft. Lbs.) torque wrench and injector nozzle socket 30mm (J 29873). Install stub shaft seal using stub shaft seal installer (J 46265) and universal driver handle (J 8092) and place the selected shims on pinion housing and install the o-ring in the groove on pinion housing. Check the bearing housing and carrier pinion housing bore for nicks or burrs. Use a light coat of gear lube to facilitate installation. Heat the carrier with heat gun (J 25070), align the housing bolt hole to the carrier bolt hole using the long bolts of flange and pinion cage remover (J 45019) as pointer, tighten the bolts, and then press the housing evenly to the bore before taking out the long bolts to put in pinion housing bolts tight, torque to 29 nm (21 ft. Lbs.). Insert the Differential assembly (100) into the Differential carrier, lightly coat the outer diameter of the oil seal may with axle lube, and use the output shaft seal installer (J 45017) to install the oil seal. Fit the carrier cover o-ring into its groove; apply a light coat of gear lube to the o-ring region; move the bolt holes into line with one another; and force the cover onto the Differential carrier evenly, starting thread of the cover bolts by hand, and finish tightening them to 29 nm (21 ft. Lbs.) in a criss-cross pattern. Finally, install the Drain Plug and tighten it 39 nm (29 ft. Lbs.), then after axle and half shaft are installed in the vehicle fill the axle with Differential lube gl75w90 gm p/n 12378261 (Canadian p/n 10953455) or equivalent and fill to the bottom of fill plug threads before installing and tightening with 39 nm (29 ft. Lbs.) plug to the fill plug.

Tighten them in sequence to 110 N.m (81 lb ft).

Position the differential on the transmission jack and secure it.

Remove the front propeller shaft from the differential and set it aside, followed by the removal of the right and left front wheel drive shafts.

The intermediate wheel drive shaft and the front differential should be disengaged from the oil pan.

Clean it in solvent and inspect for chips or cracks, damage to the bolt holes, unusual wear, grooves or scoring, damaged side bearing flanges, heat discoloration, and worn differential pin bores.

Secure the flange with the Pinion Flange Holder (J 45012) and use a breaker bar to assist in removing the pinion nut with the Injector Nozzle Socket 30 mm (J 29873).

Inspect the bearing rollers and races for pitting, scoring or grooves, excessive wear or other damage, and check for heat discoloration, which can range from faint yellow to dark blue, indicating potential overload or improper lubrication; any bearings or races showing heat discoloration must be replaced.