Here is the rear off my 55 F250.
From my Ford Truck Parts and Accessories book, it looks more like the F100 rear, but my wheels have the 8 bolt pattern.
Could someone clarify what I've got from this picture?
Also, what is the item circled? It screws into the axle and the cap spins on it but doesn't easily pull off. (don't want to break it.)


The tag for the gears says 39/8 which matches the 4.88 on my id plate.

Here is the underside:

 

Sort of looks like a vent to me!

 

Well that would make sense, now that I think about it, it did have a hole through it, but wouldn't you want one on both sides....of course I know nothing about these.

What would it be venting?

 

Others could express this better, but I think presuure builds up in the rear end from friction and oil etc... This prevents it from forcing it's way out thru the seals. Sort of like what your draft tube on the other end of the truck is for. (Farm boy version)

 

yah it it's vent it should have a hose on it clipped higher to the frame ..some of them are threaded in some are pressed in..as long as it's clean and clear it will be fie..and yah spurredon is right...

 

Not all vents have a hose attached. I have seen some like the one described here, with a loose fitting, but fixed cap on top. (Don't break it. :-o)The axle housing is all open inside, and one vent is sufficient. The rear appears to be a Dana 60. It may have a small number 60 on one of the webs at the rear of the center section.

 

Awesome, thanks for your help guys.
Yes it is a Dana 60, I wondered what that 60 was stamped on it.

Just did a google search and Wikipedia says this:
"The Dana 60 rear axle was first introduced in 1955 as a full floating axle in Ford F-250's and is still used today."

Now, at some point in time I may want to go with a lower gear ratio so I get get higher speeds. (That will be quite some time off though.) What are your opinions on either swapping gears or swapping axles?

 

This is not a Spicer/Dana 44 inspection cover (which is roundish), so the rear axle isn't from an F100.

This is a Spicer/Dana 60 inspection cover. This rear axle will be found in 1955/56 F250's (and 1957/85 F250's).

The 60 rear axle is still used today, but you won't find one in an F250 after 1985 (replaced by the Sterling 10.25).

Dana 60: 1975/2011 E250's (Econoline). Was also used as the rear axle in 1979/85 F350 4WD's. 2WD F350's used Dana 70's (1961/85).