My 47 2 ton has a 2 speed axle. It wasn't hooked up when I got it. It just has the air line coming up to just behind the cab but is not attached to anything. I can't figure out where to attach it or how to control the axle range. I have a weird looking valve in the parts box but I have no idea where it might go.

If anyone has a schematic of the system, that would really be appreciated.

 

The "air line" should/could be a vacuum line. Early models were vacuum shift. (later electric, not sure about air on bigger trucks)

Check the last couple posts about how these work, just for background. They talk about a spring loading that keeps the axle in low if it loses vacuum:

https://www.ford-trucks.com/forums/1...-problems.html

More background regarding vacuum vs. electric:

https://www.ford-trucks.com/forums/7...peed-diff.html

Electric shift--SOME of this will be the same with vacuum:

http://www2.dana.com/pdf/AXSM-0029.pdf

Bingo, a manual on ebay--best I can come up with:

Eaton 1948 2 Speed Axles Owner Manual Lot | eBay

 

Thanks for this!!! I went ahead and purchased the books on ebay. Also, being a newb, I didn't know about the large truck forum and that has opened up a whole new world for me. Thanks for your time and effort. Much appreciated!

 

I got the handbook on ebay and its perfect! It describes all the parts and how to maintain them.

Thanks again for finding that!