Tools You'll Need:
* Jack and jack stands: Essential for safe lifting.
* Lug wrench: To remove the wheels.
* Socket wrench set (metric): Various sizes will be needed. A ratchet and extensions will be helpful.
* Wrench set (metric): Possibly needed for some shock-specific nuts or bolts.
* Penetrating oil (like PB Blaster): Helps loosen rusted or seized bolts.
* Shock compressor (optional but highly recommended): Makes compressing the shock spring much safer and easier. Without one, it's much more difficult and potentially dangerous.
* Torque wrench: Crucial for tightening bolts to the correct specifications.
* Safety glasses and gloves: Protect yourself from potential injury.
* New rear shocks: Make sure you get the correct part number for your specific GMC Sierra model (1500, 2500, etc.).
Steps:
1. Preparation:
* Park on a level surface, engage the parking brake, and chock the front wheels.
* Locate your vehicle's owner's manual or a repair manual. This will have specific torque specifications and diagrams.
* Gather your tools.
2. Vehicle Lifting and Wheel Removal:
* Safely lift the rear of your truck using the jack, placing it at the designated jack points (consult your repair manual).
* Securely place jack stands under the rear axle. Never work under a vehicle supported only by a jack.
* Remove the wheels.
3. Shock Removal:
* Locate the top and bottom shock mounts. They are usually bolted to the axle and the truck's frame.
* Spray penetrating oil on all mounting bolts. Allow it to soak for at least 15 minutes.
* Using the appropriate sockets and wrenches, remove the nuts and bolts securing the top and bottom of the shock absorber. This may require some force, and the penetrating oil should help. A breaker bar might be necessary for stubborn bolts.
* Carefully lower the shock absorber. The spring will likely be under tension. A shock compressor is strongly recommended to safely control the spring's compression. Without a compressor, be extremely cautious; the spring could unexpectedly release and cause injury.
4. Shock Installation:
* Compare the new shock absorber to the old one to ensure they are identical.
* If using a shock compressor, compress the spring on the new shock.
* Install the new shock absorber, aligning the mounting points.
* Tighten the nuts and bolts to the manufacturer's specified torque. Do not overtighten.
* Release the shock compressor (if used).
5. Reassembly:
* Repeat steps 3 and 4 for the other side.
* Reinstall the wheels.
* Lower the vehicle.
* Check for proper shock absorber function. Bounce on each corner of the truck. It should rebound smoothly without excessive bouncing or swaying.
Important Considerations:
* Rust: Older vehicles often have rusted bolts. Use penetrating oil liberally and be prepared to possibly break a bolt. If a bolt breaks, you may need to drill it out and replace it.
* Spring Tension: The rear suspension springs are under significant tension. Using a shock compressor is highly recommended to avoid injury. Failing to use one significantly increases the risk of serious injury.
* Torque Specifications: Always tighten bolts to the manufacturer's specified torque. Over-tightening can damage threads or components, while under-tightening can lead to loosening and potential failure.
This guide provides a general overview. Consult your vehicle's repair manual for detailed instructions and torque specifications specific to your 1996 GMC Sierra. If you are uncomfortable performing this repair yourself, it's best to take your vehicle to a qualified mechanic.
