7459 - GM Lower Timing Gear Retainer Wedge - Atlas Engine

• Keeps the lower timing gear locked while the cylinder head is removed from engine
• Services I4, I5 & I6 (Atlas) engines
• Without this tool, the disassembly of the lower portion of the engine will increase labor time by 12hrs+ for cylinder head repair
• Make sure to follow the GM Service Bulletin “06-06-01-17C” for using the Lower Timing Gear Retainer Tool
• Failure to do so may lead to damage and additional repair steps not covered by the warranty
• Compare to GM Factory Tool #EN-48464
• It is also recommended to use CTA #5047 & GM Factory Tool #EN-46547
• Applications: (GM Atlas Engines) Buick, Chevrolet, GMC, Hummer, Isuzu, Oldsmobile & Saab
  • I6 - LL8 (Vortec 4200)
  • I5 - L52 (Vortec 3500)
  • I5 - LLR (Vortec 3700)
  • I4 - LK5 (Vortec 2800)
  • I4 - LLV (Vortec 2900)

Detailed Instructions for Use:

1. Prepare the Engine:
• Review Service Bulletin: Always refer to GM Service Bulletin “06-06-01-17C” for specific guidance on using this tool.
• Set Timing Alignment: Ensure the engine is at the correct timing position before starting. Follow the vehicle’s service manual for guidance.
• Safety First: Disconnect the battery to prevent accidental engine engagement during disassembly.
2. Insert the Timing Gear Retainer Wedge:
• Position the Tool: As shown in the illustration provided (with the tool highlighted in blue), insert the CTA 7459 Retainer Wedge into the space between the lower timing gear and the engine block.
• Secure the Gear: The wedge should fit snugly between the gear teeth and the chain, ensuring that the timing gear is securely locked in place.
• Check Proper Engagement: Ensure the wedge is fully inserted to prevent any movement during the removal of the cylinder head.

3. Proceed with Cylinder Head Removal:
• Begin Disassembly: Once the lower timing gear is locked, follow the service manual to remove the cylinder head.
• Monitor the Wedge: Periodically check that the wedge remains securely in place as you remove the head.
4. Install New Components:
• Cylinder Head Reinstallation: After completing the necessary repairs or replacements, reinstall the cylinder head. Ensure the proper torque settings are followed as per the vehicle’s service manual.
• Timing Verification: After reinstalling the head, verify that the timing is still aligned correctly.
5. Remove the Tool:
• Carefully Remove the Wedge: Once the head is securely reinstalled, remove the CTA 7459 Retainer Wedge from the timing gear area.
• Final Timing Check: Verify that the timing components are still aligned before reassembling the remaining engine parts.
6. Reassemble the Engine:
• Reconnect Components: After completing all checks, reassemble any components removed during disassembly, and reconnect the battery.
• Test Engine: Start the engine and ensure it runs smoothly with proper timing alignment.

When to Use:

Use the CTA 7459 Lower Timing Gear Retainer Wedge during any repair or maintenance procedure that requires cylinder head removal in GM Atlas I4, I5, and I6 engines. This tool ensures that timing remains intact without disassembling the lower engine portion, making it indispensable for efficient repairs.