In the process of designing our driveshaft carrier upgrades, we found that the most popular lift kit for the platform (3.5" JOR) has a drastic effect on the angles of the rear section of the driveshaft. We reached out to the manufacturer to ask if they offered a center support bearing spacer kit, and were told people didn't have any vibration or other issues after installing, so it wasn't necessary. Doing some calculations after measuring some things on our stock-height test vehicle, we found that the 3" drop of the diff relative to the body would result in a 6° change in angle of the rear portion of the driveshaft. This makes the misalignment at the rear center support bearing's u-joint go from 1.5° (stock) to 7.5°, which is a huge misalignment for a u-joint to handle. From experience on other lifted vehicles, this kind of misalignment generally does create vibration in the driveline, and the vibration coupled with the larger pinion angle at the connection to the rear differential wreaks havoc on the u-joints and support rubber while accelerating wear on the differential pinion bearings.
Our next step was to get a 3.5" JOR lifted vehicle in-house to see what was really going on. Upon our first test drive before adding any of our parts, we immediately noticed driveline vibrations under low-speed high-load scenarios like wide open throttle in 1st/2nd gear. This is the most common sign of a driveshaft misalignment, since u-joints do not spin smoothly when off by more than a couple degrees. We measured driveshaft angles and found a 7.9° difference between the rear two sections, even more than we had calculated. Angles of the 3 sections from front to back (NU/ND=nose up/down) were 3.0° NU, 0.9° ND, and 7.0° NU. For reference our stock test fit van was 0.4° NU, 0.2° NU, and 1.7° NU. We went to work realigning the drivehsaft with various spacer sizes, and were able to completely eliminate all load-based vibrations. Go figure, the configuration we settled on that eliminated all vibrations turned out to be within Toyota's spec shown in the factory service manual! The final angles were 1.2° NU, 1.2° NU, and 3.0° NU. To put them all in one place:
- Stock - 0.4° NU, 0.2° NU, and 1.7° NU
- Lifted - 3.0° NU, 0.9° ND, and 7.0° NU
- Corrected - 1.2° NU, 1.2° NU, and 3.0° NU
These spacers will prolong the lifespan of the rear two u-joints and the differential pinion bearings, while eliminating driveshaft vibrations due to severely misaligned u-joints. We recommend them for any van lifted with the 3.5 JOR kit.
SP002A0 - For use with OEM center support bearings
- 2 smaller billet spacers for forward carrier
- 2 larger billet spacers for rearward carrier
- 2 shorter bolts tailored for use with OEM forward center support bearing
- 2 longer bolts tailored for use with OEM rearward center support bearing
SP002A1 - For use with JXB driveshaft carriers
- 2 smaller billet spacers for forward carrier
- 2 larger billet spacers for rearward carrier
- 2 shorter bolts tailored for use with JXB forward driveshaft carrier
- 2 longer bolts tailored for use with JXB rearward driveshaft carrier
- 4 bolt sleeves and 8 washers that allow JXB driveshaft carriers to mount with standard bolts (instead of shoulder bolts)
Please note the SP002A1 product can be purchased together with the JXB driveshaft carrier upgrade .
- 2nd/3rd gen (XL20/XL30/XL40) Toyota Sienna (2004-2020) (AWD Only) with 3.5 Journeys Off Road Lift Kit
For OEM Center Support Bearings - SP002A0
For JXB Driveshaft Carriers - SP002A1