SixPointTwo

Hello all. I have a 2018 Silverado with original power train warranty still intact. I have had the crappy shifting since day 1. I have meant to take care of the TSB after reading about it on here for sometime. My warranty expires in a few months so I thought I’d take care of it before time runs out. So I am thinking I will call the dealer, make an appointment and have them check it out and drop the pan, change the fluid. The guy on the phone told me that I couldn’t just call and make an appointment for the TSB to be completed, that I had to make an appointment and pay $200 to have it diagnosed! Is this normal to pay for something that is under factory warranty? With my F150 anything that was problematic under warranty was covered with no fee. It had a leaking engine that they took care of for free as well as a bad battery, speakers that worked intermittently and a fob that stopped working from a distance. I love my truck but this is upsetting. I apologize if I am coming across badly I just want to hear if this is normal or if they are ripping me off.