One problem related to front suspension lower control arm has been reported for the 1999 Chevrolet Silverado. The most recently reported issues are listed below.
Initial air leak occurred approximately 1 month after delivery, the window was replaced, and has been replaced 5 other times including next service appointment, in sept. Or oct. Of this year a thumping sensation was felt through the steering wheel, after one attempt to service, dealer was unable to reproduce problem, I requested appointment with service advisor in which problem was noticed. I was told it was a lower control arm bushing and that was occurring with the 99 Silverado frequently. With that said the service advisor at parks Chevrolet in beaufort, SC 843-525-4100 stated that both the window would be repaired at the same time the front was repaired; he would order the parts; I have received no calls from the dealer.