I recently snapped the rear axle shaft, RH side, in my 1983 F250 4x4. The snap was so bad it wallered out the inside of the axle assembly. The axle shaft part is $205 at O'Reilley's so we decided to completely remove the entire rear axle and replace it with another one.

My question is what all years and styles are matches for this year of truck.

It has the 351 windsor.

Thanks for all replies.

 

Any f250 from 80-late 80's will have the same rearend you have, which I assume is a Dana 60. Some people go on up and install a Ford sterling rear in place of the Dana 60. They started putting these in somewhere in the mid to late 80's. Some people like this rearend better, and it will bolt in, but I am not sure if the driveshaft will fit. Just measure the length of the nose of the rearend. If it's longer or shorter, you will need to modify the driveshaft. I like Ford/Sterling because you can just pull the drum off without taking the whole axle apart on the end.

A quick way to tell which rearend is which; The Dana will have a oil fill plug in the rear cover. The Ford?Sterling will have the fill plug on the driver's side front casting.

P.S. I just remembered they had a lighter duty f250 rear axle. You might have one of those. It will not have the long snoot sticking out of the center of the rear wheel. If your rearend doesn't have the piece sticking out, you have the lighter rearend and I would recommend getting the heavier duty unit.

And with all this swapping, of course you need to know what gear ratio you have now.

 

The rear-end i just remembered was from an '87 F250 it does have the long hubs sticking out. How do I figure out what gear ratio I have?

 

See if it has a tag under one of the bolts. Clean it up and see if you can make it out. 99% of the time they punch a hole through the first number, so if you see "10" or "L10" it's going to be a 4.10 ratio and if you see a "55" or "L55, it's going to be a 3.55 ratio. These are pretty much the only ratios you will commonly see in these rearends in the Ford trucks.

 

Thanks for that tip. Pulled the tag and the rearend I had was 3.55

now i guess my next questions are:

can I put a newer axle with matching ratio in?

does the rear-end ratio need to match the front end?

whats the difference in the 3.55 and the 4.10? speeds?

Thanks Franklin for takin time out of ur sunday for this.

 

You probably had a Sterling in there, I would just go back with one of those. As for ratios, the rear and front ratios MUST match, or wou will likely blow something up (u-joint if you are lucky). I would stick with the 3.55 otherwise it would be a lot of work to change out both axles. In a truck I prefer 4.10's especially since I do a lot of in town driving. 3.55 will theoretically give you a higher top end since it will keep the rpms lower, BUT if you put on bigger tires and such, you might actually lose mileage with 3.55s since the engine is working harder to move more weight and will not be in its sweet spot.

 

front to rear are 1 point off like a 4:10 rear & 4:11 front
So YES you need to put a 3:55 back in unless you do both or never plan to put it 4 weel agin

 

With a 3.55 rearend, your driveshaft will turn approx 3 1/2 turns to make the tires go around once. With a 4.10 rearend, your driveshaft will have to turn approx 4 times before the tires will turn once.

So you can see your engine will rev higher with a 4.10 rearend. And like the others said, you definitely do not want the front driveshaft turning 3 1/2 turns while the rear shaft is turning 4 turns to do the same thing.