Hi, my boyfriend has a 2000 Chevy Silverado (automatic) with 140,000 miles on it, and lately it's been having problems switching gears. It'll switch gears later than it's supposed to, sometimes we even have to lift off the gas for a second to help it switch. Sometimes it won't even switch into 5th gear (but sometimes it does). Is this a problem with the transmission, or the computer, or some kind of an electrical problem? Would putting in some transmission fluid help? The check engine light hasn't come on at all. Any advice on this at all?
