~$60 Differential Case Spreader - no Welding

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Hey guys,
I'm working on replacing the gears in my Dana 25 front axle. It's a stubborn one, and no amount of prying is getting it out. I trolled the internet looking for a case spreader and everything I found ran from $200-$500 and none of it mentioned that it would work on a Dana 25. 
After checking out the various designs I came up with a DIY unit. I know it fits Dana 25. If you have something larger, you might take measurements and adjust accordingly - the legs and jack screws might not be long enough for the larger units out there.

This unit came in at about $60, minus the tools. It ain't exactly pretty, it ain't exactly light. But it WORKS.

Tools:
Cutting tool (band saw, chop saw - OR have your steel shop make all the cuts detailed below)
Ball-peen or other suitable Hammer 
center punch
1/2" corded drill or drill press
1/4" drill bit for pilot holes
3/4" drill bit for case pin holes
13/16" drill bit for jack screw holes
tool for removing sharp edges - grinder/file/sandpaper
anti-seize compound

Materials:
30" of 2"x2" square tube 1/4" wall
36" of 3/4-fine hardened (grade 8) all-thread
8 each 3/4-fine grade 8 nuts
8 each 3/4 grade 8 washers
2 each 3/4-fine coupler nuts

Legs:
1. Cut the 2x2 tubing into two 15" pieces
2. measure 1.25 inches in from each end and mark the center of the tube with the punch. Drill a 1.4" pilot hole all the way through the tube (both walls). Drill the hole to 13/16" and deburr. These are the jack screw holes. These need to be larger than the all-thread to allow the case spreader to move out-of-square as the jack screw are tightened.
3. roll the tube to an undrilled face (90 degrees). Measure 7.5" from one end of the tube. Punch, pilot and drill the hole to 3/4". This is the case pin hole. It needs to fit the case pin snugly to prevent deflection under load as the differential case is spread open. If it deflects, it could pop out of the recess in the differential case.
4. Repeat these steps for the other leg.

Cut the All-thread:
2 pieces 3" long
2 pieces 15" long
You may need to chase the threads on the cut ends to get nuts to screw on. Chase as needed.

Case Pins:
1. Screw a grade 8 3/4-fine nut onto one end of each of the 3" pieces of all-thread

Jack Screws:
1. Take one 15" piece of all-thread and screw a 3/4 coupler nut on about 4" on each end. Add a washer
2. On the second 15" piece of all-thread, repeat the last step but use grade 8 nuts.

Assembly:
Stuff it all together so it looks like this. Use anti-seize under the coupler nuts to reduce thread galling under load. You should also have nuts & washers on the outside of the lower jack screw. Somehow I only ended up with six grade 8 nuts, not eight:

Stuff the case pins into the holes. You can weld the case pin nuts to the legs to make the unit sturdier and to keep from losing parts, but it's not needed if you're just using it on the old jeep axles. If you do weld the nuts, I'd recommend cutting slots in the pins to make it easy to adjust them.

I found that I could use this without removing the axle from the jeep if I removed the passenger side spring plate.

The Willys Universal Service Manual (page 200) warns against spreading the case more than 0.020" and cautions to remove it between each use to prevent the case from taking a 'set' to the spread position. The DANA corporation warns against spreading newer models - Dana 30, 44, 60, etc. more than 0.015".

If you build one of these, let me know how it works for you so we can improve it for everyone. If you make it larger to fit a Dana 60 or something, please share the measurements!

Thanks,
Les

Edited by LesBerg - 17 Apr. 2017 at 4:33am