MaxTrac Suspension 410520 2-Inch Rear Lowering Shackle Installation Manual

1. Overview

This manual provides comprehensive instructions for the safe and proper installation of the MaxTrac Suspension 410520 2-inch rear lowering shackles. These shackles are designed to lower the rear of your Chevy C1500 or C2500 truck by approximately 2 inches, enhancing its stance and potentially improving handling characteristics. The kit includes two heavy-duty steel shackles with rubber bushings and grease zerks for maintenance.

Image 1: MaxTrac Suspension 410520 2-Inch Rear Lowering Shackles. These black steel shackles feature red polyurethane bushings and are designed for rear suspension lowering.

2. Safety Precautions

Always prioritize safety when working on your vehicle. Failure to follow these precautions may result in serious injury or damage to your vehicle.

• Ensure the vehicle is parked on a level, stable surface.
• Engage the parking brake and place wheel chocks on the front wheels to prevent movement.
• Use sturdy jack stands to support the vehicle after lifting; never rely solely on a jack.
• Wear appropriate personal protective equipment, including safety glasses and gloves.
• Do not work under a vehicle supported only by a jack.
• If you are unsure about any step, consult a qualified mechanic.

3. Required Tools

Gather the following tools before beginning the installation:

• Floor Jack
• Jack Stands (rated for your vehicle's weight)
• Wheel Chocks
• 13/16 inch Socket and Ratchet
• 13/16 inch Wrench
• Hammer or Mallet
• Grease Gun and appropriate grease (for grease zerks)
• Optional: Torque Wrench, Thread Tap (for grease zerks if unthreaded)

4. Installation Instructions

Follow these steps carefully to install your new MaxTrac Suspension lowering shackles.

Step 4.1: Prepare the Vehicle

1. Park your truck on a flat, level surface.
2. Engage the parking brake and place wheel chocks in front of the front wheels.
3. Loosen the lug nuts on both rear wheels, but do not remove them yet.
4. Using a floor jack, lift the rear of the truck until the rear wheels are off the ground.
5. Place jack stands securely under the frame rails, just forward of the leaf springs. Ensure the vehicle is stable on the jack stands.
6. Remove the rear wheels.

Step 4.2: Remove Existing Shackles

1. Locate the stock rear shackle on one side of the vehicle. It connects the leaf spring to the frame.
2. Identify the two bolts: one connecting the shackle to the leaf spring (upper bolt) and one connecting the shackle to the frame mount (lower bolt).
3. Using the 13/16 inch socket and wrench, remove the nut from the lower shackle bolt.
4. If your vehicle has a trailer hitch that obstructs the lower bolt, it may need to be temporarily removed or loosened.
5. Remove the lower bolt. You may need to use a hammer to tap it out.
6. Support the leaf spring with the floor jack to relieve tension.
7. Remove the nut from the upper shackle bolt.
8. Remove the upper bolt and carefully remove the stock shackle.

Step 4.3: Install New MaxTrac Shackles

1. Before installation, ensure the grease zerks are properly threaded into the new shackles. Some units may require threading the hole with a tap before installing the zerk.
2. Position the new MaxTrac shackle and insert the upper bolt through the leaf spring and the top hole of the shackle. Secure with a nut, but do not fully tighten yet.
3. Carefully raise or lower the leaf spring with the floor jack to align the lower shackle hole with the frame mount.
4. Insert the lower bolt through the frame mount and the bottom hole of the shackle. Secure with a nut, but do not fully tighten yet.
5. Repeat the process for the other side of the vehicle.

Step 4.4: Final Steps

1. Once both new shackles are in place, fully tighten all four shackle nuts to the manufacturer's recommended torque specifications.
2. Reinstall the rear wheels and hand-tighten the lug nuts.
3. Carefully lower the vehicle off the jack stands using the floor jack.
4. Remove the jack stands and floor jack.
5. Fully tighten the lug nuts to the manufacturer's recommended torque specifications.
6. Remove the wheel chocks.
7. Check the new ride height and ensure everything is secure.

5. Operating Considerations

After installing the lowering shackles, your vehicle's rear ride height will be reduced by approximately 2 inches. This can result in a more level stance and potentially improved handling. Be aware of the reduced ground clearance, especially when driving over speed bumps or uneven terrain.

6. Maintenance

To ensure the longevity and optimal performance of your MaxTrac Suspension lowering shackles, regular maintenance is recommended.

• Greasing: The shackles are equipped with grease zerks. Periodically apply appropriate chassis grease using a grease gun to lubricate the bushings. This helps prevent squeaks and extends the life of the components.
• Inspection: Regularly inspect the shackles, bolts, and bushings for any signs of wear, damage, or looseness. Tighten any loose fasteners immediately.

7. Troubleshooting

Here are some common issues and their potential solutions:

• Difficulty removing old bolts: Old bolts may be seized due to rust. Apply penetrating oil and allow it to soak. A breaker bar or impact wrench may be necessary.
• Grease zerks not threaded: Some units may arrive with unthreaded holes for the grease zerks. A tap of the correct size (e.g., 5/16 or 8mm) can be used to create the threads before installation.
• Obstruction by trailer hitch: If a trailer hitch prevents removal or installation of bolts, it may need to be temporarily removed or loosened.
• Bed rail interference: In some cases, the truck's bed rail seam might need to be slightly bent to allow clearance for the upper shackle bolt.
• Squeaking noise after installation: Ensure all bolts are properly tightened and that the shackles have been adequately greased.

8. Specifications

9. Product Videos

The following videos provide additional information and visual demonstrations related to rear lowering shackles. Please note that these videos may feature similar products or general concepts and might not be specific to the exact MaxTrac 410520 model or installation process.

10. Warranty Information

Please refer to the manufacturer's official documentation or contact MaxTrac Suspension directly for detailed warranty information regarding the 410520 rear lowering shackles. Warranty terms and conditions may vary.

11. Customer Support

For technical assistance, product inquiries, or further support, please contact MaxTrac Suspension through their official website or customer service channels. Have your product model number (410520) and purchase information ready for efficient service.