D44 Diff/gear Rust

1970 CJ axles should physically bolt in, but the front will be a D27 instead of your D25, and more importantly, probably have 3.73 gears where yours are probably 5.38 gears. The ‘70 axles are a lot taller gear, and if you have an F134, will be on the fringes of that engine pulling those gears.
I have to question your info regarding a ‘54 CJ5. The CJ5 wasn’t produced until 1955 model year, or do you have a ‘54 M38a1 military?
Also, where in central FL are you? I live in the Keys, but am up in the north of Palm Beach County on a weekly basis.
-Donny

 

Hi Donny,
It's a 55, and for some reason I thought the front was a D27. This is my first Jeep and I'm coming up to speed on a lot of nuances. Yes I definitely have the F134 and can see that gearing being tall for it. I'm talking to a different guy about a set of axles from a CJ3 and I'm pretty sure he said it was a d27 up front. I'll have to be careful about checking gearing, but it at least sounds like it'll bolt up.
I'm up in Cocoa, probably a couple of hours north of WPB.

 

You can quickly identify a D25 due to the front cover having a vent sticking out, unless it was swapped for a D27 cover. To better verify, the center casting will have either a 25 or 27 cast in between the ribs on the top/side. The CJ3 (A or B) should have a D25 and 5.38 gearing. Both CJ3 axles should bolt in to your ‘55.
D27’s were used starting maybe around ‘61/‘62, and by around ‘65, were the only front axle used.
-Donny

 

70 rear axle "might" be the desirable flanged D44 with 1 piece 30 spline axles.
The downside is the axle tubes are slightly larger which would require different ubolts & spring plates.
Also, if they come from a V6 Jeep, the front diff yoke will be different.

 

If the 70 rear axle is flanged, then it would be an upgrade worth investing in, even with the gearing swap.

As for the carrier falling out, you won't know what is salvageable till you run a pattern on the ring gear. As long as the carrier isn't "banging" around in the journals the chances of salvaging the R&P are still reasonably good. What would be more of an issue to me would be the chance of a carrier race spinning in the journal. That would be the first place to inspect.

If the pattern is acceptable, you can toss a couple of thousands under the non load side bearing and tighten the carrier up in the housing. Rerun the picture to insure something hasn't gone off the rails and then drive it.

IMHO, baring a set being physically dangerous to run, minor damage, rust, or some background whining during operation isn't a real issue. These Jeeps are loud, crude, and slow. As long as the diffs aren't going to fail, perfection isn't really needed.
Just my .02........

 

The rear axle in my CJ2A sounds bad, but it still gets the job done just fine. I can't hear so good anyway, and the transmission and TC make more than enough noise to drown out the rear end.