Q: How to properly remove and install the rear axle shaft and differential components on 2008 Chevrolet Trailblazer?
A: Loosen the rear wheel lug nuts, raise the rear of the vehicle, support it securely on jackstands, and block the front wheels before removing the wheel and brake disc. Remove the differential cover and allow the lubricant to drain into a container, then take out the lock bolt. For models with a conventional differential, remove the pinion shaft; for those with a locking differential, withdraw the pinion shaft part way, rotate the differential until the shaft touches the case for access to the C-locks, and avoid turning the axleshafts after pulling out the shaft to prevent mispositioning of the spider gears. Have an assistant push in on the outer flanged end of the axleshaft while you remove the C-lock from the groove in the inner end of the shaft, ensuring that on models with a locking differential, the C-lock is rotated until the open end points in before removal. Once the C-lock is removed, withdraw the axleshaft carefully to avoid damaging the oil seal, noting that it is advisable to replace the seal whenever the axleshaft is removed, and ensure any thrust washer in the differential does not fall out. For installation, carefully insert the axleshaft into the housing and seat it securely in the differential, then install the C-lock in the axleshaft groove and pull out on the flange to lock it. Insert the pinion shaft, align the hole in the shaft with the lock bolt hole, and install the lock bolt, applying a non-hardening, thread-locking compound to the threads before tightening it to the specified torque. Check the cover gasket for condition; if it is good, it can be reused, otherwise replace it, then install the cover and tighten the bolts to the specified torque before filling the differential with the appropriate lubricant. Finally, install the brake disc, caliper mounting bracket, and caliper, tightening the fasteners to the specified torque, then install the wheel and lug nuts, and lower the vehicle, tightening the lug nuts to the specified torque.