Originally Posted by NAVMAN
I dont think its wise never to replace the fluids the oil will not lubricate forever so I would change it according tho the maintenance schedule.
if you did not change it for long change it 2 times in a shorter period of time to get the bad oil out.
like change the oil now and in 2 weeks time again.
I agree. DO NOT FLUSH higher mileage transmissions as the pressure used can dislodge larger dirt particles and clog up the valve body. I'd wait a couple months before changing it again, not a couple weeks.
If you bought it used, change ALL the fluids. Don't overlook the power steering and brake fluids either. You 'can' check axle fluid on your own, but it'd be a good idea to tear the covers off and clean/check the magnets in the differential. If you want to check the fluid level, in most applications the axle fluid should be just below the plug on the diff cover.
If you've owned it since new, Ford would say change the trans fluid at 60K then every 40K thereafter, as you can only change out 25% of the fluid (or so). If you demand a lot out of the vehicle, such as towing or hard driving change the fluid every 30K.