One problem related to front suspension leaf spring has been reported for the 1999 Chevrolet Silverado. The most recently reported issues are listed below.
Shakes between 60-70mph on freeway. Dealer has replaced tires twice, front wheel hubs replaced, and shackles on rear leaf springs to eliminate shaking, no success. Truck at dealer last time for 8 weeks ( dot number: tire size: p25570rdbs ).