My 2020 Chevy Silverado RST developed a transmission shudder last week. I called the dealership and they asked how many miles I had on the truck. Told them 52k. Oh, you needed to do a 45k transmission service. Do that and it'll be okay, and the service will be $850. WAIT A MINUTE!!! The 45k interval is for severe service. My truck has never been in severe service and none of the severe service parameters laid out in the owner's manual apply to my truck. I've hauled a small enclosed trailer 400 miles roundtrip, and had the 4WD engaged probably three times in the three years I've had it.