Post by Reeper on Jul 30, 2007 23:53:47 GMT -5
Our project CJ-5 has come a long way in the last few years. We built the rear Model 20 axle as strong as we could, but it was still just a Model 20. It's inherent weaknesses still providing the Jeep with its Achilles' heel. As well, the poor axle tube design and axle seals that leaked after 6 months just had to go. We were pretty sure that the seals were leaking because the weak tubes were either flexing during our constant boulder assaults or slightly bent to begin with, either way it was time for a change.
After many heated office discussions regarding ground clearance, axle shaft strength, overall housing weight, ring & pinion gear strengths, parts availability, pinion angles and much more, it was finally decided that a Dana 44 would be the remedy for the rear of the Jeep. While a Dana 60 or Ford 9-inch seemed to be the ultimate answer, many factors went into the decision. For example, a Dana 60 or Ford 9-inch axles would be too expensive and overkill for our lightweight CJ5 with a mildly built, inline-6 mill. Moreover, the Dana 60 or Ford 9-inch have longer pinion and yokes, combine this with the lack of wheel base in the CJ-5 we would be forced to order a high pinion version of either, which is weaker than the non-reverse cut versions. As well, ordering a reverse-cut axle pre-built to our specs would set us back at least 2 grand with our tastes in lockers and disc brakes. On the other hand, building one from scratch meant expensive machining to have it narrowed to suite our needs, and still ordering a reverse cut center for the 9-inch. Besides we knew where there was a perfectly good early 70's, centered Jeep Dana 44 rear housing (yeah baby!).
Here are some interesting facts about our choices. The Dana 44 ring & pinion is actually slightly smaller than the Model 20 using the same ratio, but the Dana 44 axles are slightly larger than the Model 20, 30-spline compared to 29-splineā¦ our verdict? A draw. So the biggest difference lies in the strength of the housing itself, and the axle tubes. However, our CJ5 is a 1977, narrow track version, which makes the 70-75, centered-diff Dana 44 (which is available in some 70-75 CJ's) a perfect match for our buildup.
Now it was time to start gathering the necessary internals for the build-up. A call to Randy Lyman, owner of Randy's Ring and Pinion, had the ring and pinion gears on their way, along with their incredibly complete seal and bearing install kit. As well, NO rock crawler is complete without a locking differential, so a call to Tractech (Detroit Locker) armed us with a Detroit Softlocker for our Dana 44... the ultimate in strength. We knew that all of the carrier, axle tube and ring & pinion gear strength in the world isn't worth dog droppings unless the axle shafts were up to snuff as well, so a call to Dutchman Motorsports and we had a set of their wicked-strong Chromoly Dana 44 axle shafts complete with bearings and seals installed.
Our final task was to find a qualified and competent professional to put all of this together for us. If you live in the Tucson, AZ area then there is only one answer for all of your differential needs, Tucson Differential. Check out the installation section to see the professional assembly of a super stout Dana 44 differential.
more
www.4x4review.com/products/drive%5Ftrain/cj5-dana44.asp
After many heated office discussions regarding ground clearance, axle shaft strength, overall housing weight, ring & pinion gear strengths, parts availability, pinion angles and much more, it was finally decided that a Dana 44 would be the remedy for the rear of the Jeep. While a Dana 60 or Ford 9-inch seemed to be the ultimate answer, many factors went into the decision. For example, a Dana 60 or Ford 9-inch axles would be too expensive and overkill for our lightweight CJ5 with a mildly built, inline-6 mill. Moreover, the Dana 60 or Ford 9-inch have longer pinion and yokes, combine this with the lack of wheel base in the CJ-5 we would be forced to order a high pinion version of either, which is weaker than the non-reverse cut versions. As well, ordering a reverse-cut axle pre-built to our specs would set us back at least 2 grand with our tastes in lockers and disc brakes. On the other hand, building one from scratch meant expensive machining to have it narrowed to suite our needs, and still ordering a reverse cut center for the 9-inch. Besides we knew where there was a perfectly good early 70's, centered Jeep Dana 44 rear housing (yeah baby!).
Here are some interesting facts about our choices. The Dana 44 ring & pinion is actually slightly smaller than the Model 20 using the same ratio, but the Dana 44 axles are slightly larger than the Model 20, 30-spline compared to 29-splineā¦ our verdict? A draw. So the biggest difference lies in the strength of the housing itself, and the axle tubes. However, our CJ5 is a 1977, narrow track version, which makes the 70-75, centered-diff Dana 44 (which is available in some 70-75 CJ's) a perfect match for our buildup.
Now it was time to start gathering the necessary internals for the build-up. A call to Randy Lyman, owner of Randy's Ring and Pinion, had the ring and pinion gears on their way, along with their incredibly complete seal and bearing install kit. As well, NO rock crawler is complete without a locking differential, so a call to Tractech (Detroit Locker) armed us with a Detroit Softlocker for our Dana 44... the ultimate in strength. We knew that all of the carrier, axle tube and ring & pinion gear strength in the world isn't worth dog droppings unless the axle shafts were up to snuff as well, so a call to Dutchman Motorsports and we had a set of their wicked-strong Chromoly Dana 44 axle shafts complete with bearings and seals installed.
Our final task was to find a qualified and competent professional to put all of this together for us. If you live in the Tucson, AZ area then there is only one answer for all of your differential needs, Tucson Differential. Check out the installation section to see the professional assembly of a super stout Dana 44 differential.
more
www.4x4review.com/products/drive%5Ftrain/cj5-dana44.asp