Here's a general outline of the process. This is not a complete guide, and should not be used as the sole source of information for this repair. You'll need a detailed repair manual specific to your truck's differential type (e.g., GM 10-bolt, 12-bolt, etc.).
1. Preparation:
* Safety First: Disconnect the battery's negative terminal. Wear safety glasses and gloves.
* Gather Tools and Parts: You'll need a differential gear setup tool (to properly set pinion depth and backlash), a torque wrench, a suitable impact wrench or breaker bar, various sockets, a gear puller, a bearing race installer, and a clean workspace. Obtain new spider gears, shims (if necessary), and any other seals or gaskets that need replacing.
* Consult a Repair Manual: This step is crucial. The manual will provide specific torque specifications, installation sequences, and diagrams tailored to your differential.
* Drain the Differential: Remove the drain plug from the differential housing to drain the gear oil.
2. Differential Removal and Disassembly:
* Remove the Drive Shaft(s): Disconnect the driveshafts from the differential.
* Remove the Differential: Depending on your axle type, this may involve removing the axle housing from the vehicle or dropping the entire axle assembly. This usually involves removing various bolts, brackets, and possibly brake components.
* Disassemble the Differential: Carefully disassemble the differential case, removing the ring gear, pinion gear, axles, side gears, and finally, the old spider gears. Pay close attention to the order of components and take photos or make notes as you go. Note the locations and thicknesses of any shims.
3. Spider Gear Installation:
* Clean Everything: Thoroughly clean all components with a suitable solvent (e.g., brake cleaner).
* Install New Spider Gears: Carefully install the new spider gears into the differential case, ensuring they are properly seated. The repair manual will show the correct orientation.
* Reassembly: Reassemble the differential in the reverse order of disassembly, paying close attention to the correct positioning of all components and using new seals and gaskets as needed. This includes installing the side gears, axles, ring gear, and pinion gear.
4. Setting up the Differential:
* Pinion Depth and Backlash: This is the most critical step. Use the gear setup tool to precisely adjust the pinion depth and backlash according to your repair manual's specifications. Incorrect settings will lead to premature gear wear and failure.
* Torque Specifications: Tighten all bolts and nuts to the manufacturer's specified torque values using a torque wrench.
5. Reinstallation and Testing:
* Reinstall the Differential: Install the differential back into the vehicle.
* Reinstall Drive Shafts: Reconnect the driveshafts.
* Refill with Gear Oil: Fill the differential housing with the correct type and amount of gear oil specified in your repair manual.
* Test Drive: Test drive the vehicle carefully, listening for any unusual noises.
Disclaimer: This is a simplified overview. This repair is complex and requires specialized knowledge and tools. Incorrect installation can lead to serious damage to your vehicle. If you are not comfortable performing this repair, take your truck to a qualified mechanic specializing in differential work. They have the proper tools and expertise to ensure the job is done correctly.
