fluid question??

[cupper]

I have a 96 model f350 dually 2 wheel drive.my question I want to change the transmission fluid but dont know what to use (By the way its a straight shift 5 speed) and as far as the rear end I dont know what to use there either dont know if it is postive traction limited slip or what I dont have a owners manual to tell me anything any body no where to get a owners manual?any help would be very appreciated!!

[pipelayerjdh]

Use Mercon/dexron III or better.

For the rear, what is the axle code on the door jamb?

[cupper]

on the door jam transmission code is C and the axle code is 45 how do you know if you need to add the friction modifier?? you said to use mercon/dexron III is that the way it is listed on the bottle or what would you consider as better? Thanks for your time and help!! Bill

[cupper]

I found a sticker on the side of transmission it says fill with mercon synthetic or equilvant so is that mercon V synthetic it says its a ZF by ford. couldnt find anything on rear end it doesnt have a drain plug on the rear cover either if that helps sorry to sound so stupid .

[fordnut85]

A 45 axle code should be a 4.10 open (non-limited slip) gear so 90W is what you wanna run however I HIGHLY recomend adding a little Lucas oil stabilizer to it for good measure.