Now THAT Is the best advice by far, Never thought of that. Either way though I assume the best way is a little at a time then. I'm not real sure on this stuff I just don't want to screw anything up. Thanks

 

Draining it all at once is fine, won't hurt a thing.

 

Ok, thanks again

 

A manual doesn't have a dipstick either.

 

Jeezz, how long is a long time ? Yes, you have been using the wrong stuff...why? Do you have some sort of reason, just curious why someone would do that to their investment. Anyway, all you have to do is look in your owners manual. Don't say you don't have one, it's cop out. They are easy downloaded from the manufacturer, just like most things today.

 

You do not have to change it unless you have gone through water of somehow contaminated the existing oil. If you do change it, make sure you use the correct weight as recommended by Ford and the friction modifier as recommended by Ford. Failure to do this will trash your differential. and, change all of it at once. not gradually