Q. I purchased a used 2004 Chevy Silverado 4×4 pick-up truck about five years ago; it now has 128,000 on it. The automatic transmission has never been smooth, but I’ve noticed that when shifting from first to second gear there is a pronounced “thud’’. My local mechanic ruled out the u-joints and didn’t seem too concerned about it. I’m worried that I’ll have to replace the transmission soon. Should I bring it to a transmission specialist or am I being too paranoid?
A. I would look for two problems. The noise may not be coming from the transmission but rather the rear differential. It is possible the differential has developed some gear wear. The other issue is a valve in the transmission called an accumulator. This valve can be replaced to soften the one-two shift.