In the past several years, we've seen Jeep (as well as other manufacturers like Dodge) start using Rezeppa style constant velocity units in their front drive shafts. This is probably due more to the Daimler influence than the Chrysler influence when it comes to engineering the drivetrain components. Opinions are varied about these units but many customers opt to use a conversion drive shaft for either their Jeep Grand Cherokee, Dodge Dakota/Durango, or any other vehicle in which they have the option to change out their front driveshaft for a conversion replacement model.
The general rule of thumb when trying to decide if a conversion replacement drive shaft is right for you is this: if your vehicle is NON all-wheel drive, a conversion replacement will work for you. What is a conversion replacment you ask? Well, it's basically a drive shaft that uses a flat, forged steel flange that bolts in place of the Rezeppa constant velocity.
What are the advantages of the conversion replacement drive shafts? The main advantage is that they are more durable. Since they use a flange instead of the high speed CV unit, a typical u-joint is used that is fully greasable and is more easily changed when the drive shaft starts showing wear. The other advantage is that they are normally cheaper than their Rezeppa counterparts. This is because, again, they use a regular u-joint and flange instead of the complicated CV unit.
If you have an all-wheel drive vehicle, you're normally stuck with a Rezeppa style drive shaft unless you want to change the pinion yoke out at the transfer case to a model that accepts double cardan type constant velocity units. When installing a Rezeppa-type CV, be careful not to overtighten the bolts as this will cause the unit to bind up inside and will surely ruin the drive shaft in no time. Most of the manufacturers' specs we've seen on the torque limit is 20 foot pounds. Soon, we'll be offering a bunch of different CV rebuild kits along with instructional blog posts to help you rebuild these types of shafts.
Thanks for reading~