2012 Chevrolet Silverado 1500: Transmission clunking
Common wear/failure (not a recall)
Symptoms
Owners of the 2012 Silverado 1500 report: transmission clunking. CarComplaints.com lists 6 owner complaints, average mileage 24,400 miles.
NHTSA has 21 owner complaints for the 2012 Silverado 1500 in this area. Examples:
- NHTSA complaint ODI #11673534 (filed 07/14/2025): “I got the code p2138 and i’ve had it inspected and throttle body and accelerator pedal assembly replaced. the problem is still not fixed. i lost power driving to work and heavy vibration and shaking. if i pull out in a turn and someone is coming up fast and th…”
- NHTSA complaint ODI #11560369 (filed 12/15/2023): “While driving down interstate my transmission just went out down shifted almost causing someone to hit me from behind after some research i learned gmc vehicles have been having this problem for the last 10 years but yet keep using the same transmissions it's …”
Likely causes
Sources do not establish a single root cause; diagnosis is needed. Owner-reported fixes are listed below.
Fix, in plain English
Most common owner-reported solutions on CarComplaints.com: replace tcc valve (1 reports). Check for open recalls and extended warranty coverage with a dealer before paying out of pocket.
DIY difficulty: Pro
Diagnosis needs a scan tool; repair or replacement needs a lift, transmission jack and the manufacturer's fluid fill/relearn procedure. (Our assessment.)
Cost
No sourced cost range: get a written quote after diagnosis.
Typical parts (search links, no affiliate codes)
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