Greetings Everyone: At work today I was put in charge of keeping up on the maintenance of the two company trucks. One is a 2004 Ford Diesel 4x2 with 249,xxx miles on it and the other is a 2006 Ford Diesel 4x4 with 100,xxx on it. Both are automatics. I have read many bad things about some of these engines from these years and need all the assistance BITOG members can provide. I guess Ford had a few years where their diesels gave owners trouble. First off, there are no records that I am aware of. The trucks have been taken to the local quick lube every 10,000 miles and had the oil changed. I have no idea what is in the crankcase other than "its supposed to be 100% synthetic oil". When something went wrong or goes wrong, the vehicle was/is brought to the dealer. I would like to bring up the quality of life on these vehicles and the first place to start is the engine oil, trans fluid and rear ends. I have read a lot of good things about Shell Rotella but knowing nothing about diesel engines I need your assistance. These vehicles are used for deliveries, sales calls and basic work related transportation for a handful of employees. They are in good condition and don't have a really hard life. Besides fluid recommendations, does anyone know of a good shop I can take these to on the Eastside or Northeast side of Atlanta? Norcross, Duluth, Lawrenceville, Buford, Suwanee, Chamblee, etc. I am thinking that all the fluids need to be replaced with syn fluids. TIA for your input.