ShockWarehouse
Toyota 4Runner X-REAS: Repair and Replacement Choices
X-REAS connects diagonally opposite dampers through hydraulic lines and control absorbers. If your 4Runner has this system, decide whether to retain it or replace it with a complete conventional-damper setup before ordering individual shocks.
How X-REAS controls body movement
X-REAS links the right-front and left-rear dampers, and the left-front and right-rear dampers. The hydraulic connections let the system respond to inputs at opposite corners rather than treating each damper as an isolated unit. Toyota uses the arrangement to manage body motion during cornering and uneven-road driving. A conventional shock conversion removes that hydraulic cross-link function.
Identify the equipment on the actual vehicle
Check the suspension and vehicle specification instead of assuming every 4Runner of a given year or trim has the same equipment. Look for the connected hydraulic system and establish whether it is intact or was modified by a previous owner. If rear air leveling is also fitted, include it in the repair plan. Replacing dampers does not automatically replace air springs, a compressor or their controls.
Retaining the factory system
Have a Toyota-qualified technician identify the cause and extent of a leak or handling problem. A connected-system diagnosis is different from assessing four independent conventional shocks. Use the service procedure for the exact model and equipment. Do not open a hydraulic connection as a casual test or assume that a general shock-installation guide describes X-REAS service.
Converting to conventional dampers
Plan the complete vehicle rather than replacing one X-REAS unit with an unrelated shock. The replacement package, handling of the hydraulic components and spring or leveling equipment must work together. The installer should verify the chosen front and rear applications, travel, clearances and any alignment requirements. A conversion changes the system; it does not preserve X-REAS operation.
B6 4600 or B8 5100?
The B6 4600 family is the starting point for supported stock-height truck and SUV applications. A B8 5100 setup may be appropriate where the exact application and intended spring-seat setting support the vehicle. Do not choose a leveling position from a generic maximum-lift claim. Identify the springs, current height, intended height and suspension equipment before selecting the package.
Toyota explains the X-REAS suspension system
System illustrations
Compare the cataloged ShockWarehouse packages
The packages below are listed with two front dampers, two rear dampers and two KYB SM5640 front mounts. They use different front part numbers. Open the exact listing and confirm your vehicle, suspension and intended height before choosing a package; similar contents do not establish interchangeability.
| Package | Front pair | Rear pair | Front mounts |
|---|---|---|---|
| B6 4600 package with 24-325462 fronts | 2 × 24-325462 | 2 × 33-329093 | 2 × SM5640 |
| B6 4600 package with 24-329064 fronts | 2 × 24-329064 | 2 × 33-329093 | 2 × SM5640 |
| B8 5100 package with 24-324359 fronts | 2 × 24-324359 | 2 × 33-313146 | 2 × SM5640 |
| B8 5100 package with 24-328258 fronts | 2 × 24-328258 | 2 × 33-313146 | 2 × SM5640 |
Related guides
Frequently asked questions
Is X-REAS the same as rear air suspension?
No. X-REAS hydraulically links dampers. If the vehicle also has rear air leveling, that equipment needs separate consideration in the repair or conversion plan.
Can I convert by replacing only one shock?
Plan a complete, application-correct conventional-damper conversion. Do not combine an unrelated conventional unit with an unverified partly retained X-REAS system.
Are the two B6 packages interchangeable?
Do not assume so. They contain different front damper numbers. Match the exact package to the vehicle and suspension configuration.
Will a conversion retain X-REAS function?
No. Conventional dampers do not retain the hydraulic diagonal cross-linking of X-REAS.
