Big lift, big tires, big wheeling trips…. you’ve now embraced Jeep life in a BIG way and you are also starting to find parts that are not holding up to all this BIG action. Driveshafts are one of those items that take a lot of abuse, especially if you are running a tall lift. The driveshafts in the Jeep JL, like the previous model JK, use CVs at both ends on the rear driveshaft and at the transfer case end of the front driveshaft. They are a wear item and a weak point in your Jeep’s drivetrain. As you start to lift a Jeep, the CVs are operating at a steeper angle, which will cause the rubber boot to tear, allow water and debris in, causing wear, then vibrations and ultimately failure. In the JKs, it was lifts taller than 3″s and 50-70,000 miles before it started happening. For the JL, typically driveshafts start to become a requirement at or past a 3.5" lift or if your shocks extend longer than 28". However, its never a bad idea to upgrade to heavy-duty driveshafts even if you're running less than 3.5" of lift! The CVs in the Wrangler JLs and JT's have a new, slightly larger CV, but they are still just a simple CV with a rubber boot, which will see the same problems as the older JK CVs. The CV on the left is from a JL with 15K miles on it. The JK CV on the right was ran with a lift and had around 80K miles on it. The boot was severely thrashed, the CV was packed with dirt and it had worn out enough to cause a serious vibration while driving down the r...