ARB Air Locker Engagement Ring with Wave Spring (050904SP)

This is the part that does the locking.

Inside the ARB Air Locker, the engagement ring slides across and locks the side gear forcing both axles to drive together when you need it most.

If your locker isn’t engaging cleanly, slipping, or making noise, this is usually why. Wear, shock load, or bad engagement habits take their toll. 

Comes with wave spring.

Suits:

Selected ARB Air Locker models

Common applications including Toyota, Nissan and other 4WDs running compatible ARB lockers

Always confirm your ARB locker model before purchase

Bottom line:
If your Air Locker isn’t working like it should, this is one of the first parts to fix it.