So i'm at about 67k miles on my 03 4.7L. I was wondering if it would be necessary to do a full system flush anytime soon. I was thinking radiator, oil (duh), both diff's (4x4) and anything else?. I bought the truck about a year ago and i have no clue what kind of maitnance was done before me. I would like to get the most out of this bad boy. Any clue when i should do this, certain mileage or what not? Or if it's even necessary....

Hontz

 

Coolant flush and refill every 5 years/100k miles and the differentials can vary but most like to do them every 30k miles. Does your truck have the anti-slip rear (LSD)?

 

whenever i buy a used vehicle, i just assume that nothing has been done, and everything is due. things you should probably take care of, but might not necessarily essential are: transmission fluid (either flush, or drop pan and filters), engine oil (might run some seafoam or marvel mystery oil through it), transfer case, both diffs, plugs and wires.