Shop OEM General Motors Part # 23153929. Coil Spring (Rear). CTS; w/Ride & Handling; Code AATM. Sport suspension, w/o chassis control, code: AATM. Suspension Coil Spring -

Spring - Coil.
Code-8AG,9AG. Coil Spring.

Coil Spring

Fits CTS

CTS; w/Ride & Handling; Code AATM. Sport suspension, w/o chassis control, code: AATM.
Suspension Coil Spring - Repair or Replace
Your coil springs are not especially prone to failure, but if they have been cut, clamped, or heated to have the vehicle lowered, your might benefit from replacing the strut springs. Excessive rust can make the springs more prone to failure. Contact your local service department to have your suspension system evaluated.