Please click any of the brands below to see the Torsion Keys we carry for your Sienna:

What is a torsion key? Why buy them?
According to DJM Suspension, "To understand what a torsion bar key does we need to take a look at the whole torsion bar front end. First, a torsion bar is really a spring. It works just like a coil spring except it twists instead of compressing and expanding up and down. The word torsion means - to twist, and a torsion bar is a long bar lying parallel to the frame and the ground with both ends of the bar fixed. One in the frame and the other end is fixed in the lower control arm. As the lower control arm cycles up and down it twists the torsion bar because the other end is fixed in the frame and cannot spin. Torsion bar diameter and length will determine the rate of the bar, just as the wire diameter and the number of coils determine a coil springs rate. The lowering torsion bar key works by changing the indexing of the bar, rotating the hexagon shaped mount. When your truck is setting still, there is a certain amount of weight being held up by the torsion bar. This weight or load is a designed amount and dictates how high your truck sets. The lowering torsion bar key by rotating the index (hex shaped mount) causes that designed load to occur at a lower ride height, while everything else stays the same.