The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2018 Sierra 1500 Transmission Shudder & Hard Shifts - What's going on?

0

Mark S. · rep 0 · May 22, 3:48 AM · 1 replies · solved · Question

Hey everyone, I'm having some serious issues with my 2018 GMC Sierra 1500 SLT, specifically with the 8-speed automatic transmission. Lately, it's been shuddering pretty badly, especially when accelerating from a stop or at lower speeds. It also feels like it's shifting really hard between gears, almost like it's slamming into place.

I've heard about some issues with these transmissions, but I'm not sure if it's a known defect or something I need to worry about immediately. The truck only has about 60,000 miles on it.

Has anyone else experienced this with their Sierra? What was the fix? Is this something covered by a TSB or extended warranty?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 3:48 AM

0

ClearTheCode guidance (Gmc · Buying & ownership)

Summary: For 2018 Sierra 1500 Transmission Shudder & Hard Shifts - What's going on?, work through these steps on your 2016+ vehicle:

  1. Confirm the symptom — note when it happens (cold start, highway, after fuel fill, etc.).
  2. Scan codes — save all pending/stored DTCs; don't clear until you've recorded them.
  3. Check TSBs & recalls — look up your VIN for open campaigns and known fixes.
  4. Inspect the obvious — related fuses, connectors, fluid level, and recent repairs.
  5. Test the common fix — follow model-specific service procedures; one change at a time.
  6. Escalate if needed — burning smell, no brakes, overheating, or stalling in traffic → shop visit.

Owner reported: Hey everyone, I'm having some serious issues with my 2018 GMC Sierra 1500 SLT, specifically with the 8-speed automatic transmission. Lately, it's been shuddering pretty badly, especially when accelerating from a stop or at lower speeds. It also feels like it's shifting really hard between gears, almost like it's slamming into place.

I've heard about some issues with these transmissions, but I'm n…

This is educational guidance, not a substitute for hands-on diagnosis.

Menu

Help & account