I have a 1984 ford wood truck with a 302 eng and a 4 spd trans with a borg warner transfer case. (it an old beater but pulls like a horse). I was haulin a big load of fire wood and the back rear end went out. I've tryed to call the auto parts places to find out what gear is in the rear end and which rear end i have,) they tell me theres 23 diffrent gears for the 84 f-250). The say i could be a dana 40 or dana 60. I have no idea how to tell them apart. I have the same problem with the data plate off the rear end i dont know how to read the numbers that are on it. I need to find out wichg gears are in it so i can get anther gear or just replace the whole rearend out of a junk yard.

 

Two things -

Look at the rear cover. If there is a filler plug in the rear cover, it is a Dana. If not, it is likely a Ford/Sterling 10.25. Ford did not use a Dana 40, not even sure if the Dana 40 exists.

Look at the center section of the rear. It should have a "60" cast into the webbing.

Drop the rear cover, and there should be a set of numbers stamped into the ring gear (41-11 = 3.73, 41-10 = 4.10 and so on) . That can tell you the ratio. You can also count the teeth on the pinion and divide it into the number of teeth on the ring gear. That will also give you the rear ratio.

Is it a 2 wheel drive? If so, and it is a beater, then rear end ratio might not matter so much if you just replace it with a junkyard rear end.

 

If you still have the door jamb tag on this truck, and believe it's the original rearend, then read the code and we might be able to figure out what you have from that.