A front end clunk on 2007–2013 GMT900 trucks is one of the most complained-about issues — and one of the most misdiagnosed. The clunk can come from several sources. This guide walks you through isolating it and fixing it right the first time.
Most Common Clunk Sources
1. Upper Control Arm Ball Joints
The most common culprit on GMT900 trucks. The upper ball joints are integrated into the upper control arms (same as GMT800) — the joint cannot be pressed out and replaced separately; you replace the whole arm.
How to check: Lift the front end under the lower control arm. Grab the tire at 12 and 6 o’clock and rock it. Any clunk or movement at the upper joint = replace the UCA.
Fix: Front Upper Control Arms with Ball Joints for 2007–2016 Silverado/Sierra — forged steel arms with pre-installed ball joints, direct bolt-on replacement.
2. Sway Bar End Links
The sway bar end links are a common wear item on GMT900 trucks. When they’re worn, you’ll get a clunk over bumps, especially during slow parking lot turns.
How to check: With the truck on a lift, shake the sway bar — any clunk at the end link connection points means it’s worn.
Fix: Replacement end links are under $20/pair and a 20-minute job.
3. CV Axles (4WD trucks)
Worn CV axles can make a clunking or clicking sound — especially on turns (outer CV) or under hard acceleration (inner CV boot failure).
How to check: Turn full lock in a parking lot and accelerate gently. A clicking noise = outer CV joint worn.
4. Front Strut Mounts (2WD)
GMT900 2WD trucks use struts in the front. Worn strut mount bearings can cause a metallic clunk over bumps that sounds like it’s deep in the suspension.
How to check: Park on level ground, have a helper push down on the front bumper while you listen at the strut tower.
Diagnosis Tip
Reproduce the clunk with the truck on a lift and have a helper turn the steering wheel lock-to-lock while you watch each suspension component. This helps isolate the exact source without guessing.
Alignment After Front End Work
Always get an alignment after replacing upper control arms. The GMT900 uses camber adjustment via offset bushings in the UCA — the shop should set this during alignment.