SPOOLOGIC Unison Ring

The SPOOLOGIC Unison Ring — SL-270-021 replaces the vane-control ring inside the turbocharger on the listed 2004.5–2016 Duramax applications. It links the VGT mechanism to the vanes for coordinated exhaust-flow control.

Features

• Replacement VGT unison ring
• Application-specific vane-pin slots
• For servicing a worn or damaged vane-control ring

What's Included

• 1 SPOOLOGIC Unison Ring

Fitment

• 2004.5-2005 Chevrolet Silverado GMC Sierra 2500 3500 6.6L Duramax LLY
• 2006 Chevrolet Silverado GMC Sierra 2500 3500 6.6L Duramax LLY
• 2006-2007 Chevrolet Silverado GMC Sierra 2500 3500 6.6L Duramax LBZ
• 2007.5-2010 Chevrolet Silverado GMC Sierra 2500 3500 6.6L Duramax LMM
• 2011-2016 Chevrolet Silverado GMC Sierra 2500 3500 6.6L Duramax LML
• 2006-2007 Chevrolet Express GMC Savana 2500 3500 6.6L Duramax LLY
• 2007.5-2008 Chevrolet Express GMC Savana 2500 3500 6.6L Duramax LMM
• 2009-2010 Chevrolet Express GMC Savana 2500 3500 4500 6.6L Duramax LMM
• 2010.5-2016 Chevrolet Express GMC Savana 2500 3500 4500 6.6L Duramax LGH

Turbo Applications

• Garrett variable-vane turbochargers

VGT Control

The unison ring engages the vane pins so the vanes move together. Inspect the vane pins and ring contact surfaces during repair, and verify that the mechanism moves freely after assembly.

OEM and Manufacturer References

• 721913-0001
• 721913-0003

⚠️ DIY Product — All Sales Final, No Warranty, No Returns

This SPOOLOGIC turbocharger repair product is intended for experienced turbo builders and qualified technicians. Proper installation requires suitable tools, careful inspection, and correct assembly. All sales are final—no warranty, returns, or exchanges. Confirm compatibility before ordering. See the SPOOLOGIC Warranty Policy for details on products sold without a warranty.