If you are running more than 2" of lift on the rear of your 2016+ Titan (non-XD) you probably need one of these drive shaft spacers to ensure the drive shaft slip yoke seats deep enough into the transfer case to not wear out or cause binding as the suspension cycles. Basically, Nissan made the drive shafts too short (this has been a common inssue since 2004) and they continued this issue into the later generation. These are NOT for the 2wd or 2-pc drive shafts...only the big 'ol aluminum ones. We have been machining the old style for 15+ years and realize the newer trucks need this fix also. The old style uses 12mm bolts and the new style uses a much bigger u-joint with 14mm bolts. The new style drive shafts also have a metal sleeve that covers the spines on the yoke going into the t-case, so you cannot simply see how far the drive shaft is actually pulled out when lifted. watch the little video to see....it's a lot. These spacers are made from 6061 and use 10.9 metric hardware and are a close tolerance fit to ensure no vibration. Installation is really easy, you don't even need a jack. Simply park the truck on level ground, apply the parking brake (park will not hold the truck with the DS disconnected). Remove the 4 bolts at the rear axle pinion (these can be overly tight from the factory..big wrench and maybe heat), slide the DS into the t-case a bit, put the new 4 bolts through the ds flange, place the spacer on the pinion flange, slide it back together and put the nuts on and tighten. if the DS holes dont line up prefectly do to the DS rotating a bit, just put the shifter into N and the DS can rotate freely. torque to around 150ft/lbs. We machine these right here in-house and generally have them instock. but we are NOT Amazon and it can take a day or two to get them on the truck. Includes USPS shipping in the 50 states. We will gladly ship globally, but shoot us an email with you address to get a quote w/ shipping.