Of the many changes and additions that Chrysler decided to make on the all new 2007 model Jeep JK Wrangler, I think few have seen more furrowed brows among those in the Jeeping community than has the decision to use drivelines with disk type CV joints.
Now, I should point out that there’s absolutely nothing new about the idea of using drivelines that have CV joints and certainly companies such as BMW, Ford, GM and even Chrysler have all attempted to use this setup in the past. In some cases, they still use them on cars they make today and with good results. Without a doubt, there are even some advantages to using CV joints, one of which is a smoother operation over conventional U-joints. In fact, if the new Jeep JK Wrangler were a vehicle that was never going to be lifted and was expected to spend all its time on pavement, I’m not sure anyone would have even taken notice of the these new drivelines.
Of course, the reason for all the consternation regarding these new drivelines stem from the fact that the whole purpose of owning a Jeep (especially a Wrangler) is to take it off-road. And let’s face it, many of the people that will ultimately own a new Jeep JK Wrangler WILL in fact lift its suspension and modify it for use on extreme terrain. The problem is, CV joints are not designed to operate at continuous increased angles or under greater torque loads that a lifted Jeep with larger tires will create.
Among other things, such as the potential to break your drivelines with larger than stock tires, binding of the CV joints which can prevent them from operating smoothly or the possibility of the balls being force out of the front or back side of the CV joint while the driveline is fully compressed or at a full droop, the most likely problem you will encounter is the one that will happen over time. When CV joints are at a constant increased angle, their boots will be pinched and this will cause them to rub continuously. Needless to say, this constant rubbing will ultimately cause the boots to wear out prematurely and tear. This is where your real problems begin. With a torn CV boot, the grease inside of it can now be contaminated with dirt and water, both of which will lead to the eventual failure of the CV joint itself.
If you’re planning to lift your Jeep at all, I would highly recommended that you budget in the cost of new front and rear drivelines. And, to date, the only company that I am aware of that manufactuers and sells aftermarket drivelines for the Jeep JK Wrangler is J.E.Reel Drive Lines.
Currently, J.E. Reel is offering three different drivelines for sale, the first of which is a 1310 Series unit that bolts right up to the existing O.E. flanges. The second is a 1310 Series unit that utilizes a pinion and transfer case yoke that is more conventional with U-Bolts. And, last but not least is 1350 Series unit that utilizes flanges and yokes with U-Bolts for those demanding superior strength in their drivelines. J.E. Reel drivelines can be purchased direct or as a part of Full Traction suspension lift kits.
Special Thanks: I would like to give special thanks to Jim Reel from J.E. Reel Drive Lines for providing me with the information I needed to write this article and Mel Wade from Off Road Evolution for helping me to get photos of these drivelines being installed.
NOTE: When using a drive shaft with a double cardin joint, it is important that you remember to adjust your pinion angle accordingly through the use of adjustable rear upper control arms in order to prevent diveline vibrations. This is especially important on 2-door model Jeep JK Wranglers that are lifted 3″ or more as the lenght of the rear drive shaft is exceptionally short.