I recently bought a high milage automatic 7.3 1996 f350 PSD and have a few questions/problems.

It's leaking transmission oil and rear differential oil very slowly.. Maybe a half cup of transmission oil in a week, and an 1/8th cup of rear diff oil in the same amount of time.

This truck didn't come with a manual, so I'm not sure what types of fluid to use when I replace the gaskets. The guy at auto zone said to figure out if it's mercon or mercon 5... And asked if I have a heavy duty axle or light duty axle for the rear diff. I'm guessing heavy, but I don't know.


I also can't find the fill hole for the rear diff.. Am I missing something?


I'd really love to find a good shop manual for this truck, but All I can seem to find is for the gas version.

Oh, Also... When I check the trans fluid level, there is a thin layer of fluid on the dip stick, but not at all like when checking the oil (Where it is very noticable where the level is at) Could this just be some residue in the tube that is wetting the dipstick? (I guess my question is, should it be a very definitive line on the stick where the level is at?)

 

the axle takes syn 75/140. the plug is on the drivers side front of the pumpkin, you need a 3/8" ratchet to remove.

 

the tranny fluid is dexron/mercon but ford has approved merc-v for use as well. the fluid should be pretty easy to see when the truck is running, wouldnt hurt to change all the fluids on any new, used truck

 

Haha... There was a thick coating of grime and mud on it... Completely hid the thing.
Took a screwdriver to it and broke it off in chunks. Thanks. Found it.