I was told by a service advisor that a technician recommended changing the transfer case fluid when I was at my dealer for an oil change at 25,000 miles. I deferred it and took a look at the owner's manual showing changing transfer case fluid is recommended at 45,000 miles. Changing automatic transmission fluid and filter is also recommended at 45,000 miles as well which the service advisor did not even mention at all. I searched a little bit... some dealers also recommend it at 45,000 miles.... In addition, the owner's manual recommends changing engine oil every 7,500 miles but my dealer says it has to be done every 5,000 miles. Of course, they are using Dexos oil. I just checked the engine oil right before going to the dealer and it was pretty clean. I am confused these are the same trucks made by Chevy and official Chevy dealers use OEM oil/fluid/parts, but how can this maintenance schedule be different? They are just trying to make money? My friend, who is a local mechanic (he is not doing trucks), says transfer case fluid is pretty clean when he changes it at 100,000 miles for CR-Vs and other SUVs. I am driving my truck 100% on-road, barely putting some light objects on the bed, and never towing or off-roading. I think it is better to stick to the owner's manual. Am I missing something?