Question: I ran across a set of Dana 44s out of a '70s Scout for $400. Would these be a good upgrade for my '79 CJ-7? How much width would I gain?
Answer: The flange-to-flange distance on a Scout 44 is about 59 to 59.5 inches. I believe your CJ-7 is about 56 inches. There is a difference of about 3 to 3.5 inches, so that means track width will increase about 1.5 to 1.75 inches on each side, depending on tire size and rim backspacing.
However, before you just jump in and start on the swap, keep in mind that there are a couple of drawbacks to the Scout axle as compared to the Jeep axle that will become very apparent once you start the swap. Personally, I like the Scout axles and use them under my own Jeep. You just have to learn how to deal with them.
Let's start with the back first. You get some 1.31-inch-diameter, 30-spline flanged axles and some 11x2-inch brakes. Each axleshaft is the same length, so that makes it handy for only having to have one spare on hand. (OK, you should always run an axle in the same direction and not swap side-to-side, but for a "get-you-home spare," it's just fine.) However, what this means is that the pinion is offset and the driveshaft will not line up directly with the transfer case. Is this a problem? Not really, as long as both ends of the shaft are on the same plane and you don't have a lot of downward angle. I have run them like this for years without any major problems. Naturally, you're going to have to cut off and remount the spring perches at the proper width for your frame and correct pinion angle.
Now let's go to the front, where things get a bit more problematic. Overall, things look good. Big disc brakes (same as an early-CJ disc-brake setup), heavy eight-bolt spindles, and 1.5-inch-diameter, 30-spline axles. The Scout frame was wider than the Jeep frame, and you'll notice that the differential housing is quite stoutly braced, right where the spring has to mount on the right side. Plus, the offset is a bit different than what is on your Jeep. By the time you cut enough room for the spring to properly fit, you've weakened the housing quite a bit and you really don't have a place for an inside U-bolt. I have seen a lot of modifications done here, and none of them are very nice. What I've done on a stock Jeep frame is to put the front spring outboard of the frame, which means custom-built new spring mounts as there are no kits available that I know of to do this. While you're at it, you might as well do a shackle reversal. Even with the springs set at an outboard stance, the clearance is tight. OK, we're good here, right?
Now look at the steering knuckles. IH chose to make the steering knuckles quite stout and the steering arms quite long. Good thing about this is that it offers lots of clearance for the tie rod and differential cover when in a tight turn. Bad thing about this is that Scout also used a very long pitman arm off the steering box. Your present steering-box mounting location is too far rearward to allow clearance for the longer arm. Yes, the Scout arm will bolt right up to the pitman shaft on your present steering box. No, you cannot use the Jeep pitman arm-the shorter length of it will drastically prevent full left and right turning. So this leaves you with a couple of other modification choices. You can redo the mount and move the steering box forward for proper clearance, and have great steering. Or you can swap the steering knuckles for those off your Dana 30 front end-they are interchangeable. Please don't think that you can redrill the steering arms closer to the knuckle. I have seen some people do this but do not recommend it. There is really not enough material left around the hole. This makes for some marginal strength, and steering is not the place that you want to sacrifice strength.
Now comes the real problem. Scouts, because of the way the spring mounts and other factors, use only 0 degrees caster angle. I believe the '80 Scout used maybe 1 degree. Your Jeep was designed to use something like 5 to 7 degrees of caster angle. Remember, caster is pretty important, as it's what keeps you going down the road straight. OK, you set your spring pads to get the 7 degrees and then take a look at your pinion. It's pointing downward! The only way to correct this is a heck of a lot of work. You have to cut free the weld at the steering knuckles and rotate them, hopefully equally on both sides, until the pinion angle is correct, and then reweld them. Not an easy job. Dana did one heck of a good job of getting deep penetration on the welds. Believe me, it is one hard job. I made up a fixture to do mine in, and I believe I ended up rotating them about 15 degrees to get the proper pinion angle and caster angle for my application.
Still ready to make the Scout front axle swap? Maybe not? I am going to give you a second choice. Use a Jeep Wagoneer front Dana 44 axle. They are about the same width as the Scout axle and have the proper caster built into them. OK, they have six-lug bolts. Not a problem. Chris Overacker at Code 4x4 in Rifle, California, turned me on to this many years ago. You use a Ford hub rotor assembly from a '76-and-later F-150 (PN EITZ1102C) along with the Jeep wheel bearings and a Ford seal (PN C9TZ1175C).
One more thing: Just in case you come up with a screaming deal on a Wagoneer, you can use the rear axle too. Swap out the left rear axle for Jeep PN 994294, which is a 5-on-51/2 bolt pattern. (This may be an old, no-longer-used part number, but a good parts guy should be able to cross it over to the new number.) It's too long for the right side, so you will have to have someone cut it down and respline the end. Yes, I've seen people weld up a couple of the stud holes and have it redrilled to the proper pattern, but I think it's easier and safer to go with a new axle.