Well for me my 2014 Silverado crew cab Z71LTZ transmission lasted for about 110k miles and started the hard shifting and now at 118k it started slipping and shuttering. Took it to dealership last week and was told it was toast and not re-buildable and that I was looking at 5k to replace it with a new updated transmission. Now I also took it to the same dealership for transmission service at 75k they flushed it and refilled. So now until I can fix I have a 30k paper weight for a truck. Had Chevy trucks my entire adult life but it's looking like that will need to change because after we the people bailed out GM they are nowhere to help bail us out.