There are many different ways to build a drive shaft for the new JK. One method uses an adapter flange which bolts directly to the original pinion flange. This is really not much more than a round flat plate with bolt holes drilled into it and a conventional drive shaft weld yoke welded into the center. This then bolts to the stock pinion flanges. We just don't think this is as “clean” of a modification as can be done. What if the weld yoke portion breaks? You could have a tough time finding a new one or repairing the old one. There is also a concern with maintaining the accuracy of the part after welding. In addition to this, the center of the universal joint gets pretty far away from the pinion bearing. Excessive overhung load is not a good thing.
***In picture below, this shows the stock flange and adapter that competitors use on the left. Tom's version is shown on the right.***
With Tom's version, They've elected to make a replacement flange for the differential pinions. These flanges are machined from solid billet steel. Tom's does not believe this flange will ever break. Tom's designed this to accept standard "off the shelf" mating flanges. If these flanges ever break, you at least stand a chance of getting a replacement part from almost any drive line shop. This also nets a longer drive shaft with the center of the universal joint closer to the pinion bearing.
Tom's can build either drive shaft in 1310 or 1350 series. Unless you plan on beating the vehicle really hard, we believe the 1310 series front drive shaft would serve most people well. Likewise for the rear drive shaft.
These prices are for the complete package including required nuts, bolts, and flanges/yokes. We can supply a good fit by application information only but believe we can get the best fit if you will supply a simple length measurement.
If you want the best then this is the drive shaft for you. I've got plenty of good responses from this thread and sold a few solid JK drive shafts. Just give me a call and let me explain your options and why Tom's shafts are probably the right choice. I will also help you to determine if you should roll with the 1310 joints or the 1350's. Its easy guys...