How do I know if I need LifeGuard 6 or LifeGuard 8?

Identification is based on your specific transmission model:

  • ZF 6-Speed (6HP Series): Requires ZF LifeGuard 6 ( S671.090.255).
  • ZF 8-Speed (8HP Series): Requires ZF LifeGuard 8 (S671.090.312).

The VIN Check: Always check your VIN because some vehicle models switched transmissions mid-year.