I have some transmission questions I need answered. I have a 17 3500 srw 4x4. I drive a lot of highway miles and I’m almost at 100k. I haven’t had the transmission fluid drained and replaced. I went to a local shop and asked about having it done there. The service manager basically told me that if I do replace the fluid and filter that I will burn up the transmission in a few months. This is because the bits of trash in the fluid would not be there anymore to make up for wear that may have occurred. Does this sound legit to anyone? I am about to start occasionally pulling a travel trailer and I don’t want to get stranded. I thought that with modern synthetic fluid and filters that this doesn’t make sense. FYI the truck has all the factory goodies for towing goose neck, fifth wheel, etc. I appreciate all input.