I have an '03 Silverado w/ the 4.8L in it. I just purchased it. It has 62,000 miles on it. Here are the symptoms. It usually happens at low RPM's, but say for instance i have to slow down a bit at the beginning of an incline, and then when i step down on the gas to get going, it shifts hard, not as in difficult but as in harsh, when it shiftsinto gear. Also, sometimes when just coasting through our park, at low speed (5-10 mph) it seems to not shift down. I have a 3 month, 3,000 mile warranty on it so i want them to fix it, but wondering what it could be. Any suggestions? Some kind of sensor maybe? Thanx, Jim

 

no check-engine light?...I'd get it checked for codes anyway though

 

Nope, No check engine light. I'll check with the dealer just to make sure.

 

@ 60 thousand miles you are supposed to get the transmission fluid changed and everything checked out.

 

Hey all, Had my local dealership put the truck on the Diagnostic OBD2, and no codes, so thats a good thing. They told me, they will do that, if the transmission doesn't know what gear to go into, where i let off at the bottom of the incline, then stepped back on it to go up the hill, the transmission don't know which gear to shift to, hence the irratic shifting noise. I'm not sure if any maintenance was done for the 60,000 mile check up before i bought it or not, but i don't have the extra $$$$ right now to do that stuff, but i will, thanx all, Jim