Overseas Dana 44 for a YJ
I came across an SJ rear Dana 44 on eBay, which are super rare near me (I'm a service member in England, so there are zero American axles around me), and I jumped on it without much thought.
It's from a '78 SJ, narrow-track width, 4.09 gearing, coming out of a Quadratrac vehicle. So, the rear differential is offset, which I've never heard of until now, and I couldn't really tell from the pictures.
I can find astounding little information on this axle, nor people who have successfully swapped it. Most magazine articles reference how great old Wagoneer axles are, without mentioning to steer clear of the Quadratrac ones with rear offset differentials.
Now that I'm stuck with it, what are my options? Try to get rid of it? Can I run it with the offset diff? Double cardan drive shaft? Or should I just pay a shop to center the diff by replacing/ cutting down the axle tubes? Obviously, I'd have to shorten one axle shaft and replace the other.
I've been hunting for axles for my YJ for a while, especially the rear, to replace the D35. I'm just planning 35-inch tires and a locker... for now.
I'm open to ideas. And I'm open to coughing up the money to make a good axle, without any heartburn. Live and learn and think about taking a better look at the eBay pictures next time. Now I know.
Chris P. via email
I'd like to start out by saying thank you for your service. Your sacrifice is greatly appreciated. I have swapped a few axles around under a few different Jeeps and so I feel confident giving you some leads to follow up on. But first let me start by saying your eBay found SJ Dana 44 may be best passed to the next off-road fan. They are a great upgrade for earlier Jeeps with the Spicer 18 transfer case which has a passenger side off-set rear output (think 1941-1970 CJs). I'd tell you to run one of those transfer cases, but they would be less than ideal in a YJ, probably aren't easy to find, and you'd have to find a new front axle since the front output would be offset to the wrong side for your YJ (meaning you'd have to source even more difficult parts to find).
Now getting back to your eBay offset axle; while a good axle shop could re-tube your Dana 44 housing building a centered axle, it's not an easy job to do that properly. The general method is to cut out the old axle tubes and press in new ones. It's not so much the cutting the old axle tubes out of the housing as pressing the new ones in that's difficult. That takes some specialized knowhow and the proper kind of axle press. So, finding a shop that can do it might be difficult. And if you find a shop that can do it for you, you'll almost certainly end up putting a ton of money into that axle...way more than it's worth even being as rare as it is. You could try running the offset axle in your YJ, but the rear driveshaft would vibrate itself into oblivion in no short order. The rear drive shaft in a YJ is short and would have to be at a pretty severe compound angle to even turn the rear pinon. Sell the offset SJ 44.
First, I'd start looking for some Jeep XJ Cherokees in junkyards (the boxy ones sold between 1986 and 2001). Sometimes, and sadly rarely (although more common in 1989s for some reason), these XJs have a Dana 44 rear axle from the factory. That would be an easy swap and have the same bolt pattern as your YJ. All you'd need were some new spring perches and shock mounts, a welder, and some time. You'll also want a brake proportioning valve to turn down the brake pressure going to the larger rear drums from the XJ.
Second, if this XJ Cherokee axle is impossible to find (and it may be) I'd tell you to look for a rear axle from an Isuzu rodeo 4x4, which I believe was also sold in Europe as a Holden Frontera, an Opel Frontera, and maybe as an Isuzu Mu. They were also sold in the US as a Honda Passport, but I believe that was North America only. They have a 6-lug Dana 44 rear axle (the 6-lug pattern is the same as a 1978 SJ, Toyotas, Chevy Trucks, Nissan trucks and more). The older 4wd Rodeo/Frontera/Mu with leaf springs in the rear (1990-1997 I believe) are the best ones to steal the rear axle from since they later ones with coil springs use a Dana 44 based axle that won't be as easy to get aftermarket parts for. The axle you'll want will also have disc brakes which is another upgrade. The only issue for you is the 6-lug axles won't match your YJ wheels much like the SJ Dana 44 wouldn't have. You may be able to get the axles re-drilled or get custom axles with the YJ's stock 5 on 4.5? Alternatively, you could try to get your front wheel hubs to match the 6-lug pattern by piecing together knuckles and spindles from Dana 44 parts, I know you can do that with older Dana 30s, but I am not positive it will work with a YJ Dana 30. Lastly, and maybe one of the best options besides the XJ rear axle, (but also means finding more, hard to find parts) is to look for a 1980 or newer SJ (Cherokee or Wagoneer) front axle. It will be a Dana 44 with 6-lug wheel hubs, and it will be driver drop (which you'll need for your YJ). It will fit in place of your Dana 30 front axle and will be an upgrade over the 30 for sure. You'll have to run 6-lug wheels, but those at least, are plentiful.