If your vehicle is showing suspension feels like it's slamming hard over minor bumps, here are the most likely causes and the parts you'll need to fix each one.
The shock absorbers or struts have lost their hydraulic fluid or gas charge. Without this damping force, the suspension cannot absorb impacts, causing the vehicle to crash down onto the bump stops over minor imperfections.
The rubber insulator at the top of the strut assembly has degraded, torn, or collapsed. This allows the metal strut shaft to slam directly into the vehicle's body structure, creating a harsh, jarring impact.
Bump stops prevent the suspension from bottoming out harshly. If they have rotted away from age, or were mistakenly left out during a recent strut replacement, the suspension will slam violently at the end of its travel.
The coil springs support the vehicle's weight. If they are fatigued or broken, the vehicle sits lower than normal and has reduced suspension travel, causing it to easily bottom out over minor bumps.
The rubber bushings that isolate the control arms from the frame have completely failed. This results in harsh metal-on-metal impacts and a slamming sensation when the suspension cycles over bumps.
On vehicles equipped with air ride, a leak or failed solenoid can cause the system to depressurize. The vehicle will drop completely, leaving it riding directly on the axles or bump stops with zero suspension travel.