I bought a rear axle from a guy and all he could tell me about it is that it came from a 2001 2 wheel drive diesel.
it doesn't have the BOM tag, so no help there.

What I can tell you about it
3.5 inch axle tube dia.
Disk brake
8 lug
3.55 LSD
71 inch Wms to Wms

On the bottom of the webs on each side of the differential housing " 70-U2" is stamped

Thanks for any and all information

 

Pretty sure the build number is stamped in the axle tube, but from what you describe, sounds like a 01-02 Dana 70 out of a 3/4 ton.

 

I was unaware that there was a disc brake Dana 70. I thought all the disc brake rears were 80's, but this sure seems to be a 70.

 

Yep, the Auto trucks got the 70, even with discs......

 

Designated 2001.5 by most, introduction of standard 4 wheel disc brakes on 2500/3500, although some appeared as far back as 99....

 

How do you recognize a 70 and 80?

I have a 2001 4x4 looks bigger than a 70

 

The Dana 80 axle tubes get bigger [4 inch IIRC] right behind the backing plate.
The Dana 70s are the same diameter the whole length 3.5 IIRC
70 and 80 is also cast into the axle housing.
It is cast into on the right hand side lower webbing next to the diff. cover IIRC.

 

Did they use different RA's for different options, IE trailer tow?

 

Dana 70s came in the auto 2500s
The auto 3500 dually trucks and ALL manuals came with Dana 80s.
We are talking diesel trucks ONLY here of course.

 

And the V-10's.......

Never pass up a V10 in the junkyard for running gear, trans, etc.....

 

Mine is cast on the passenger side "08" at a 45 degree angle...

That's and 80 upside down...

 

This may help you out. Dodge Ram Axle Specifications

Also, the disc brakes were introduced in 2001.5 but because of tooling and assembly line supply, you can find some 2001 trucks with discs "and" you can also find some 2001.5 trucks with drum brakes. The same rule of thumb goes for many of the changes which took place in the 2001.5 and 2002 model changes. Some have them, some dont because it merely depended on what the assembly had left in stock before they re-tooled.