On an 89 F250 4x4 is there a drain on the front differential? I can't find a drain plug and I thought I read in a manual that you have to pump it out is that true? Cause that would be crappy way to change fluid.

 

you either have to pump it out, or remove the pumpkin from the TTB arm...

 

There's a boss on the bottom of my D44TTB for a drain plug that was never drilled by Dana. If you have a steady hand, drill and tap it. I did so about 12 years ago with the diff in place and it worked well.

First, I marked the hole with a center punch and drilled the pilot hole with the oil still in, so all the chips would be flushed out. Yeah, a little messy at the end! You have to make double sure this first hole is drilled perrendicular to the boss surface! I marked the second drill (the tap sized one) bit for depth so as not to drill too far in. Buy a tapered pipe tap (I went half-inch), tap it carefully (with grease in the recesses of the tap to catch chips) and then flush ithe diff well with a light oil before installing the drain plug. I took the extra precaution of running a small magnet up into the holes to fish around for any chips (which were not found) and then used a magnetic drain plug with an Allen head. Now it's easy to change front diff oil. I admit to sweaty armpits at the time. It's a "do it right the first time" kinda moment, but not beyond a person with a steady hand, good bits and taps, and patience.

 

I drilled a hole in the bottom of the hump for the ring gear and welded a piece of a 1/2" pipe splice on the housing and put a 1/2 pipe plug in. That is kinda hard with out a welder handy though.