- Dec 12, 2018
Since we started building suspension products for the second-generation Xterras, there has been an ongoing struggle to solve an annoying rear driveline vibration issue that cropped up periodically. Although very rare at 2 inches or less of lift, a few individuals were more susceptible than others and just about anyone with more than 4” of rear lift was getting a dull vibration around 35mph. This applied to any method of lifting more than 4”, whether using a mini-pack, shackle, full replacement race-type spring pack, or any combination of lift. I pride myself on knowing the vehicles we sell parts for inside and out and it was really driving me nuts trying to figure out what the problem was. It wasn’t until I went big with our own Xterra that I was able to track down the cause of the issue. The problem lies in the fact that Nissan uses a CV joint at the pinion (differential) end of the driveshaft and a u-joint at the transfer case. A CV joint can operate somewhat vibration-free at just about any angle in its operating range, but a single u-joint should really have no angle on it (an exception is if two u-joints are used, one at each end of the drive shaft; they work “out-of-phase” at equal and opposite angles and run vibration free). Many Xterra owners, after lifting the rear, would try a pinion shim to help with the vibration issue. Typically the results were maybe a slight improvement, but they were not a cure. The shims will try to zero the CV joint that doesn’t really need to be zeroed, yet the u-joint at the transfer case still has a bunch of angle (although possibly less due to the shim raising the pinion which can help to alleviate the u-joint angle slightly). Some Jeep models will drop the transfer case a bit to help this issue, but this isn’t an option on the Xterras. If only Nissan would have built the drive shaft with the joints flipped, then a simple shim would cure everything. There are two options available to cure this issue. A double Carden joint or a CV joint at the front will cure the u-joint vibration, but, as of right now, this is fairly expensive and requires custom parts. The other option, and this is what we have done, is to replace the rear CV joint with a 1350 (one ton truck) u-joint to counter the front factory u-joint. Some shops have just replaced the CV joint with a u-joint and we do not recommend this fix. The problem is that the driveshaft gets rather short between the joints and this increases the angles on the u-joints. We have found a different pinion yoke that replaces the factory CV/pinion adaptor that allows us to run a u-joint very close to the pinion and lengthen the driveshaft about 3”. The u-joint is much, much stronger than the factory CV joint. This design requires no shims be used. Now, not everyone will have an issue with driveline vibration and some may have a very slight vibration they don’t even notice. But for those that are experiencing issues, we’ll be offering a new driveshaft assembly to make this fix as easy as possible. The new driveshaft assembly will come complete, but it does require that the slip yoke (the part that goes into the transfer case) be reused, will require disassembly of the factory u-joint, and a good impact gun is required to remove the pinion nut. The whole job should take about an hour to complete. The best part is that you keep your old driveshaft so that if you go to sell the vehicle or have an issue, you do have a back-up. Price for the new complete shaft will be around $350 shipped and it will be available on the website soon. UPDATE: WE NO LONGER SELL THIS