Owners of various rear-leaf-spring-equipped GM vehicles may complain about a rear leaf spring slap or clunk noise (most apparent on irregular road surfaces).
This applies to the following:
1999-2008 Chevy Silverado 1500/2500
2000-2008 Chevy Suburban 2500
2002-2008 Chevy Avalanche 2500
2003-2008 Chevy Express 2500/3500 vans
1999-2008 GMC Sierra 1500/2500
2000-2008 GMC Yukon XL 2500
2003-2008 GMC Savana 2500/3500 vans
Do not disassemble the main spring pack or remove the bushing from the spring. Verify that the leaf spring inserts are present on the leading and trailing edges of the overload spring (second stage leaf). The insert(s) may have broken apart from wear and have fallen out. If the inserts are missing, replace them.
NOTE: On some models, the vehicle may need to be raised to allow the springs to separate enough for insert service.
Inserts for single leaf with overload spring 15247030
Inserts for multi-leaf spring assembly 15604067