|From the Archives: Narrowing a Dana 44 Front Axle to Fit a CJ||Short Cuts|
From The Archives: Narrowing a Dana 44 Front Axle To Fit a CJ
|1978 narrow track Cherokee axle, before cutting it down.|
|Partially stripped axle, before cutting it down.|
|Measuring for the cut.|
|Part way through another Dana 44 project, both inner knuckles are removed.|
|This is a Dodge Dana 44 front being narrowed to CJ width. It's ready to have the inner knuckles put in place and caster set.|
|After cutting the axle down. The small piece of tubing was removed from inside the knuckle, the larger was removed from the main part of the tube.|
|The axle, ready to have spring perches and shock brakets welded on.|
Over the years there has been much written about shortening axle housings, but it has been rare to ever see anything written by anyone not associated with one of the large axle building shops. Many of the articles that have been written would lead you to believe that this is not a job that can be done in a home shop. Until recently, campfire talk pretty much agreed with this. The old rumors about needing a 50 ton press, expensive tools, alignment fixtures and secret knowledge have all been laid to rest as do-it-yourselfers got into axle work.
No two Dana 44 projects ever come out exactly alike becuase no two Jeepers ever have the same vision for the perfect Jeep. I have helped with many Dana 44 projects since the first version of this article was published two years ago and they all come out a bit different. The one comon theme is that everyone has been happy with that they built becuase they did it their own way and built their front end to their own specifications. I have been very pleased with my Dana 44 front end, and after two years I can report no problems.
I started with an axle housing from a narrow track '78 Cherokee. I have since learned that a better choice would have been an axle Wagoneer or narrow track Cherokee with disc brakes produced from 1974 to 1977. The reason these axles are better than the '78-'79 axles is completely in the outers. The inner axle shafts and housings itself are the same. The earlier disc brake outers have the correct spindle to use F-150 hubs and rotors and they have the flat top knuckles that are desirable for high clearance steering conversions. It is possible to gather the knuckles and spindles from other sources, but it is more convient to get them in one package. A more in depth discussion of housing and outer choices can be found below.
Narrowing the Housing
I started by setting the Dana 44 in front of my Jeep and measuring. The spring pads were about 32 inches apart, 4 inches wider than on my CJ. The overall length was around 61 inches from wheel mounting surface to wheel mounting surface and my CJ widetrack front end was 56 inches. The distance from the spring pads to the wheel mounting surface was pretty close to my CJ, so I reasoned that I could leave the short side alone and shorten the long side about 4 inches. This agreed with all of the information I had gathered, so I decided to go ahead with the project.
I also checked caster and pinion angles. My CJ had about 0 degrees of caster, the spring pads were parallel with the floor as mounted in the Jeep and the pinion was about 5 degrees up relative to the floor. This isn't the standard way of measuring pinion angle. I was just trying to measure the relative angle between the spring pads and pinion angle so I could duplicate it on the new front end. Next I measured the Dana 44 front end. With the spring pads parallel to the floor the pinion was 12 degrees up and caster was at 0 degrees. This is a very good thing, it meant I could rotate the housing 7 degrees. The end result would be a pinion angle of 5 degrees up (relative to the floor) and 7 degrees of caster without cutting and turning the inner knuckle on the short side. This increased caster translated in good road manners despite the Jeep getting a Spring Over conversion before the end of the project.
The first step was to remove the brakes, rotors, spindles and outer knuckles, shafts, and differential carrier. This is all well documented elsewhere, so I won't go into detail here. I stripped it down to the bare housing except I left the pinion in (no reason, I just didn't feel like removing it). Next I used a 4" grinder to remove the spring perch and shock mount from the long axle tube. I gouged the tube a bit in doing this so I welded up the gouges and ground them smooth again.
Next I re-cut the spring perch that is cast into the center section to give me the proper pinion angle. I had to take off more than 1/4" of metal at one end and taper down to none removed at the other. I started by setting the axle on jackstands with a third jack stand under the pinion. I carefully adjusted and shimmed the jackstand under the pinion until I had the housing positioned just right. I set it up so that the final pad angle would be correct if I held the grinder level. I installed a new wheel on the grinder and started at the thick end. I pushed the grinder across using the edge to cut away the metal, stopping to check the angle several time. Eventually I was finished. The spring pad looks great and is perfectly flat. I am very pleased with the results, although it did take a long time and I went through 3 grinding wheels. In retrospect this step was entirley un-neccessary for me becuase I ended up welding on a new perch on top of the casting for a spring over cenversion before the axle was installed in the Jeep. This step may still be neccessary for those staying spring under or for those starting with a Chevy or Dodge housing and needing to change the pinion angle.
The next step was the actual cutting of the tube. I brought the housing down to my friend Tim Norstad's house because he has a chop saw and is always generous with his tools. I had already measured and marked the tubing at home. This is not difficult, just remember that the tube sticks into the inner knuckle about an inch and mark the cut in the appropriate place. I'm not going to give an actual measurement here because every project is different. The tubing wasn't any more difficult to cut than any other piece of metal that size. After the tube was cut to size I had a short piece of tube still attached to the inner knuckle. Tim and I cut that tube off as close to the knuckle as possible.
Later I clamped the inner knuckle in my vice and started grinding off the bead and old tube where it attached to the knuckle. The guys in my club said to grind until I just started to see a line or crack between the tube and the knuckle. Their next suggestion was to press out the old tube with a hydraulic press. I didn't have a press at the time so I tried hammering it with a 3 lb hammer and punch. This did nothing. Then I put the knuckle back in the vice, took my hacksaw apart and put the blade through the center and reconnected it. I made 2 cuts about 90 degrees apart and then easily drove out the pieces of tubing one at a time. Looking back, this idea was one of the most innnovative of the project and has saved considerable time and frustartion for many people.
This left me with a free outer knuckle and a tube it needed to go on. I had heard that I would definitely need a press for this part but I had done it all myself so far, I wasn't going to stop here without at least trying. I cleaned the rust and weld splatter off the tube and ground a small bevel all the way around the edge. I started tapping the knuckle on with a 1 lb ball peen hammer. It was working. I had to hit it hard, but not so hard I was worried about bending or breaking anything. I've done this several times since, and it was no fluke that my inner knuckle went on without any undue difficulty.
After the outer knuckle was on 1/2" I stopped and set the caster. To do this I set the housing up on jackstands again, this time I set it so that the surface for the nut of the lower ball joint on the still attached knuckle was level. Then I tapped the free knuckle until it matched. From here I drove it on the rest of the way, stopping may times to measure. After I had it in place I spent 2 hours with a tape measure and angle finder making sure everything was right. I tack welded it and let it sit for a week before I spent another hour measuring again. I've done more of these since and my confidence level has increased. Setting the caster angle with a good angle finder has yeilded good results every time. I no longer measure and re-measure, I just set it to where it should be and weld.
Welding the knuckle to the housing was next. If you aren't sure about your welding skills or your welder doesn't have a high enough amp rating it would be best to leave it to a professional welder. One important note is that the weld doesn't actually carry the weight of the vehicle because the tubing sticks into the inner knuckle about an inch. I have heard of people butt welding the knuckle to the tube (they didn't remove the old tube from the knuckle, just cut it flush and rewelded) but this sounds incredibly weak and dangerous to me, not to mention the difficulty of lining up the pieces. The fact that the tube is so far into the knuckle and such a tight fit in the knuckle gives me the confidence to know it is strong and lined up properly.
I re-installed the outer knuckles, spindles, and rotors to check out the front end using the original Wagoneer parts. The actual distance from wheel mounting surface to wheel mounting surface was 57 inches. I later decided to switch the front end from a 6 bolt pattern to the 5 on 5 1/2" wheel bolt pattern. Using earlier spindles and F-150 hubs and rotors widened the axle to an even 58", which turned out to be a perfect match for a Scout II Dana 44 rear end.
After careful measuring I sent two long side inner shafts to be shortened, one for immediate use and one for a spare. Dutchman Motorsports in Portland Oregon did the work and their machining looked excellent. I also welded on spring perches for a Spring Over Axle Conversion (Look for this article to come out of the archives for March) and had a friend machine the knuckles and build arms for a high clearance steering conversion . My outers consisted of Wagoneer stub shafts, flat top knuckles from a '76 Wagoneer and spindles from a '76 Wagoneer with disc brakes, late '70s F-150 hubs, rotors, bearings and seals and SuperWinch internal type lockouts meant for a 1/2 ton truck. These parts have held up well and I can report no failures, not even water in a wheel bearing, after two years of hard trail use.
There are many possible outer setups for a Dana 44. One of the most comon is to use CJ outers with Scout II stub shafts. CJ outer knuckles will bolt onto most Dana 44 inner knuckles with no problems, making this an easy swap for CJ owners who build their Dana 44 to the same width as their Dana 30 and desire to keep their same steering and brakes. This is a good combination, but leaves you with the bolt on style lockouts from the CJ. Bolt on lockouts can work loose and leak water into the wheel bearings and they are not as strong as the internal style lockouts used on 1/2 ton trucks.
1/2 ton truck outers are a step up from re-using CJ parts. The stub shafts are a bit thicker and the internal type lockouts are stronger and less likley to leak water into the wheel bearings. There are several combinations of parts than can yeild a 5, 6 or 8 bolt wheel pattern. The outer knuckles from most open knuckle Dana 44s will interchange, but there are some oddball parts out there so be sure to measure and compare.
A common setup is to use '77 or earlier Wagoneer or Chevy outer knuckles and brakes combined with '77 or earlier Chevy or Wagoneer disc brake spindles and F-150 hubs, rotors, bearings and seals. This combination yeilds a 5 on 5 1/2" wheel bolt pattern and has 1/2 ton outers. These knuckles have the flat top needed for a high clearance steering conversion. The '77 and earlier disc brake spindles are specified becuase in '78 the inner wheel bearing was made larger in Chevy and Wagoneer outers and the F-150 hubs and rotors will no longer work. Replacement parts for Chevy and Wagoneer brakes are among the cheapest and these brakes also have the reputation of working well in vehicles much heavier than a CJ.
Chevy or Wagoner parts can be used if a six lug outer is desired. Chevy or Ford can be used to make eight lug outers. It is also possible to use Ford outers to get the 5 bolt wheel pattern, but in most cases these will have a larger spindle index hole and different spindle bolt pattern, limiting them to 5 and 8 bolt wheel patterns and Ford brakes.
The housing is the basic raw material you need to start with. There are many choices for a Dana 44 front housing, too many to discuss them all. In general, start with an open knuckle housing with the differential on the correct side for your Jeep. Older, closed knuckle housings typically have thinner axle tubes and aren't worth narrowing.
I've mentioned the Wagoneer housing and this have become my favorite for several reasons. Wagoneer housings typically have 3/8 thick tubes or better. Only one side needs to be narrowed to fit a wide track CJ. They are plentiful and inexpensive. They work well with 2" (CJ) or 2 1/2" (YJ) width springs. They lend themselves to Spring Over or Spring Under easily and they have good caster and pinion angles to start with. In short, a Wagoner housing can be used for almost any small Jeep application.
I am frequently asked about using Scout II Dana 44 housings. The Scout II housing is the same width as a Wagoneer housing and already has the 5 on 5 1/2" wheel bolt pattern and outers silimar to a CJ. I don't reccomend Scout II housings for several reasons. The primary reason is that Scout II housongs have zero caster, except for a very few produced in 1980 with 3 degrees of caster. For comparison, a Wagoneer housing typically has 7 degrees of caster. Caster helps the vehicle track straight down the road and gives the steering system it's ability to return to center on it's own. The caster problem could be fixed by cutting loose both knuckles and turning them, but it is much easier to just start with a Wagoneer housing. Another drawback to the Scout II housing is the long steering arms which require a very long Scout II pitman arm to get a full turning radius. It's easier for most CJ owners to just use CJ outers or 1/2 ton outers. A third drawback is that Scout II housings can only esily accomodate 2" wide springs and Spring Under suspensions, a major drawback for hardcore Jeepers.
Wider housings from Chevy and Dodge fullsized trucks can work great. They are typically setup for Spring Over from the factory, and there is plenty of material there to make them almost any width a CJ owner could want. You will need to narrow both sides of these axles, but it's really not much harder than narrowing one. Ford front Dana 44s generally have the differential on the wrong side for a CJ, but they are great to narrow down to YJ size.
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