CAD vs non-CAD housing strength

[fixmysix]

Looking at doing a HP Dana 30 swap. I can get the CAD version of the axle basically for free, and the non-CAD that I'm finding are around $350+. I'm going to be changing shafts and gear ratio, so the inner seal and two piece shaft isn't an issue. Would I be losing any strength by using a CAD housing? Are there any other issues I'm not seeing?

 

[freedom_in_4low]

I don't have any empirical data either way, but I was in the same boat here in Colorado Springs. Non-CAD axles were pricy when you could find them, and CAD axles sold for parts (as in, sell the shafts, knuckles, and brakes and end up in the black).

I didn't get a whole lot of useful responses on the forums so I eventually talked myself into the idea that the big cast CAD housing would be stronger than the dinky little Dana 30 axle tube and went for a CAD axle. They used CAD axles all through the 80s in the XJ and YJ and I couldn't find any hint of housing failures in significant numbers any more than the axle tube. The upper control arm mount is part of the cast housing and seems super beefy. They're thought of as being weak axles but as far as I can tell it all centers around the CAD system, not the housing itself. I don't do jumps or compete at KOH or Baja so I don't think my application is going to be anywhere near the worst a CAD axle has survived anyway.

I had it geared for 4.56, put the regular CAD housing seal in and also the seal in the inside end of the CAD-side axle tube. I used the shafts, knuckles, and brakes off my TJ and used new ball joints and unit bearings. I cleaned up my TJ passenger side axle shaft down to 400 grit emery cloth where the CAD housing seal rides, and used that as well as my TJ knuckles, and new ball joints and unit bearings. I've only got 1000 miles on it but so far so good.

 

[tworley]

If anything you'd be gaining a little bit of strength due to that cast housing.

$350 is a ridiculous price for a hpd30.

 

[Jerry Bransford]

Go for the CAD and just cover the CAD opening with a piece of stiff sheet metal with screws. The CAD box actually makes that side of the axle a bit stiffer/stronger. There are CAD filler plates available but I don't have a direct source off the top of my head.

 

[freedom_in_4low]

There are CAD filler plates available but I don't have a direct source off the top of my head.

This is the one I used:
https://www.amazon.com/gp/product/B0078UA8RK/?tag=wranglerorg-20

It doesn't come with a gasket, so I bought one, forgot I had it, stuck in on with Ultra Black, and found the gasket last week...beyond the return window by a few months.

https://www.amazon.com/gp/product/B000FQ0FTU/?tag=wranglerorg-20

The worst part of the job is finding the right seal to go in the inner end of the axle tube, where the TJ axle seal would have gone. They apparently used at least 3 different axle tube thicknesses over the years so you have to find the one that fits.

The first one I tried came from Stu Offroad's writeup and crossed to a Timken 223050, which has an OD of 1.969". It fit my axle tube like a hotdog in a hallway and the shop I was paying for my gear swap just finished the job without the seal, so I had to pull the carrier back out when I got it home so I could measure and try out more seals. Mine ended up taking a 2.00" OD seal which I got from NAPA. I can't find the NAPA number, but this Spicer seal from ECGS looks like it's probably the same one:

https://eastcoastgearsupply.com/i-7139411-dana-30-inner-axle-seal-one-piece-axle-conversion-2-0.html
The NAPA 11800 with a 2.004" OD is also a common one I found people using and is so close that it may be the same as the Spicer one I linked above...and may even be the one I used. ECGS also has one for a 2.062".

 

[fixmysix]

Good info all around. Thank you guys so much. Yeah, some of the Jeep yards are asking $500 for the hpD30. I talked to one guy and he says he tosses the CAD housings for scrap. That cost difference gets me most of the way to CroMo shafts. Stay tuned for my upcoming TJ-6 build. I'm going to lengthen a TJ frame and put my 1963 CJ6 body on it. I'm sure I'll have a ton more questions in the coming months. Thanks again for saving me $$ and the seal info. First beer is on me!