I just got a 98 F150 XLT Extended Cab with overdrive and a 4.6L and the owner's manual say the transmission fluid needs to be changed about every 12K miles! Is that correct? If I had an E40D transmission it never has to be changed. What's the true story? Which transmission do I have and how often does it really need to be changed?
Thanks

 

I believe the spec is every 21k miles on those transmissions. A cooler will help the fluid last longer.
Alan

 

Somethings not right there....... I have a separate "Scheduled Maintenance" book that says (off the top of my head) that the trans is supposed to be serviced at least every 30k miles. Did not specify what model of transmission you had, other then it was for automatic transmission equipped models.....

The only thing I recall the service manual stating that "never needed service" was the differential fluid, BUT that's only if it NEVER gets submerged in water.......

I have the trans serviced once a year, regardless of mileage and I've also replaced the diff fluid because I figured 100k miles was more then enough....... Fluid is a whole lot cheaper then parts, so it was no big deal....

Good luck!

Mitch