Q: What steps should be taken to clean and inspect the differential case, pinion gear, ring gear, pinion flange, and bearing components on Cadillac STS?
A: 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.