[Force Fed Mopar]

Just wondering what kind abuse the stock D44 CAD in my 90 RC will take. I'm starting to think about building it nto a solid trail rig, and not really planning on going taller or wider than 35x12.5 tires. If I drive it properly, will it hold up with this size? Will it require CAD elimination and locking hubs, or no? I think heard there was a cable conversion for the CAD, is that "better" than the vacuum system?

 

[Elwenil]

The CAD axles are still a D44 and will be breaking axle joints and shafts if you wheel 35s hard like any other D44.  Aside from that, there are some failures that are specific to the CAD axles.  The most common failures I have seen are in the actuator and are more of a lack of maintenance or simple part failure kind of issue, though it does disable the axle most of the time.  The second most common failure I have seen is a bent housing as they do not take abuse or excessive weight very well.  I personally would not waste my time or money "building" a CAD D44.

 

[Force Fed Mopar]

So I guess the next question is, what's the easiest way to do front and rear D60's? Buy late 80s/early 90s 1 ton stuff?

Since my tire size limit was kinda being dictated by the diff strength, with D60's  should be able to run up to a 44" tire with no issue, correct?

 

[Elwenil]

The easiest way to do front and rear D60s is to get them out from under a '75-'93 Dodge truck and swap them in.  The '94 and later front axles do not use leaf spring suspension and are driver side drop so they will not bolt in and would take a lot of fabrication to make them work.  They are also CAD D60s with ball joints and unit bearings and are not considered to be as strong as the old kingpin D60s.  GM D60s of the same era as our old trucks can be used either by bowing the leaf springs to fit their slightly different spring perch dimensions or using offset spring hangers like Jungle offers.  The rears are pretty easy and all you really have to do is make sure the width is close to stock.  Spring perches on a rear axle are easy to grind off, move and weld back on in a location that fits your truck.  You could use a D60, D70, GM 14 Bolt, etc.  It could also be a worthwhile upgrade to find a later model full floating axle with disc brakes.

As for running 44s, the "no issue" thing is very subjective.  I run 37s with my D60s and while I haven't broken anything but a very old axle joint, I could easily scatter parts of them all over the ground with my granny gear, provided the driveshafts didn't fly out first.  With the torque multiplication of the low gears you can do a lot of damage, even with a weak engine like my stock TBI 318.  With an automatic, you don't have that kind of gearing and the torque converter can soften the shock loads, but the potential is still there with a large engine, large tires and low axle gearing.  Even guys running the 2.5 ton Rockwell axles can break things under the right circumstances.  But generally D60s and other "one ton" axles are decently strong and can take a lot more abuse than stock 1/2 ton axles.  I personally would not run more than 35s or 37s with D60s on the trail.  With lockers and lower gearing you would probably want to look at aftermarket alloy shafts and axle joints to beef them up.  But a lot depends on your truck, it's power and weight, gearing, tires, transmission, transfer case, the trails you run, etc.

 

[75whiskey200]

I never really broke the CAD on my 87.  It quit working because the vac diaphragm went south, but some quick measurements and a handful of flat washers and a bolt to hold the fork in place took care of that.  Threw on some locking hubs and went back to snapping u-joints. 

swapping in a 60 meant surfing craigslist for a decent deal, fixing what ails it, then bolt it in.  Mine was a direct swap, except for the front shaft, which was shorter.  doesnt cost a whole lot to have a competent shop cut it down. 

I knew a fella who ran trails with 37s on a Dana 30!  But he was very good at it and didn't just barge through. 
a doofus like me running 31s still needed dana 60s to keep from snapping axles. 

You can run as big a tire as your driving style allows.  It's pretty subjective. 

 

[GUT]

I have broken U Joint at axle to stub axle 2 times with stock CAD dana 44. Both times passenger side, and with only 31" tires. Now have 60 front and 35" tall tires, and no breakage. Yet.

 

[Blauram]

personally I'd run what you have until something breaks then fix it or upgrade it.  Just my opinion.  get out and have fun!

 

[maxt2014]

  I had to swap out the Cad 44 front years ago after running 35's. The drivers side axle tube developed a very slight upward bend to it, so it would chew out the outer axleshaft bearings every couple of months.
If you had one of these, you could find a 70's full time 4wd 44 and swap the outer knuckles onto it. I went Big block on that truck so it got 60's front and rear.

 

[SuperBurban]

I broke a upper ball joint, and bent the C end of the axle tube, And the top shock mount. Lesson learned, the 86 RC is not made to go airborne.