M38A1CDN2 vs CDN3 rear axle ass'y
 

Can one of our gurus here confirm something for me? I went to install my newly rebuilt CDN3 rear end into my jeep. I had NOS U bolts which worked with the CDN2 rear end that was in it but it appears the CDN3 has a larger tube diameter. It looks like the CDN2 is around 2-1/2" while the CDN3 is around 2-3/4". Does this sound familiar?
I am probably just going to get some new U bolts made up at the larger size and slot my U bolt plates if neccessary. I may be able to "squeeze" the larger U bolts together to fit the plates without mod.

As soon as I saw your title I knew what it would be about. Yes, they were a different size tube. There was a CFTO detailing the changes required to change a Cdn3 axle over to a CDN2 axle: you are just doing the opposite.

I would not recommend slotting Cdn2 plates. They were prone to cracking in the first place...taking more meat off them will not help. They would certainly be easy enough to make in the first place and you should be able to salvage the shock pins from the old ones for the new plates.

Chris you have a new nickname
 

You are finding all the miserable little nuances that make the Cdn3 harder to work on than the Cdn2. Everytime you touch a tool to something, it changes from normal to WTF. Your new nickname is something like $hit Magnet.

Thanks Rob. I purchased NOS M38A1 generic plates from the US, thats why I figured slotting might be OK. Maybe I can weld up a couple holes and re-drill them rather than fabbing up new ones. So, I take from your response that CDN3 plates were vehicle specific? Its weird because I bought generic front plates as well and they fit up just fine...
The Ubolts must have been a different NSN# as well?
BTW, Terry, not far from the truth!

Chris...Old pal...
 

It is likely I will be wrecking a Cdn 3. All the items you need are there.

Be patient . I know you want it all today....but........

Peter S

The U bolts were a different NSN as were the plates. When American dealers say "generic M38A1" they mean from 52 until about 1964. They don't seem to realize that they were not the only customers in the world. They especially will not recognize the differences between any other M38A1 and the Cdn 3 model.

Your efforts at fixing a Cdn3 will not be unrewarded. The production changes made for them were really a plus.

OK, here is the result; I had 4 new U bolts made at 2-3/4" inside measurement.
The plates that I bought NOS work. I did need to squeeze the u bolt slightly to get them through the holes, but I was able to do this by had with very little squeeze. The axle is now in place and ready to go.
For bearing pressing, I fully reccommend going to use a shop that specializes in this type of thing. My friend runs a large shop that rebuilds heavy truck transmissions and differentials so it was easy. Even their shop press worked to seat everything, a do it yourselfer at home would be shafted, so to speak.
I am happy with my CDN3 and dismiss all the nay-sayers out there. I can see the advantages of the upgrades. Really, the parts are out there if you look. Afterall, I have worked on a lot tougher vehs than this to find parts for and somehow I did that. I think these jeeps are a little gem, and, if no one else out there likes them good for me!
My 3 is almost ready for a safety now, just a couple brakes lines and some tweaking.
I have done:
front springs incl new u bolts, plates, shackles and hardware, NOS shocks
rear springs incl new u bolts, plates, shackles and hardware, shocks
new rubber axle snubbers all around
new tie rod ends
I rebuilt drag link ass'y
I rebuilt bellcrank
new brakes, all around incl new shoes, wheel cylinders, flex lines and steel line
rebuilt master cylinder
fully overhauled rear differential
Plus, added all the missing do-dads, radio gear, made a wire cutter etc etc