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2017 C300 Transmission Service - Rough Shifts After 60k Miles

0

Paul Z. · rep 0 · May 22, 4:19 AM · 1 replies · solved · Question

Hey everyone,

My 2017 C300 (W205) with about 65,000 miles has started shifting a bit rough, especially from 2nd to 3rd gear. It's not terrible, but definitely noticeable compared to how smooth it used to be. I'm wondering if it's time for a transmission fluid and filter change.

I remember the dealer mentioning it's a "lifetime" fluid, but I've heard from independent shops that's not really the case for Mercedes. What's the recommended interval for the 9G-TRONIC transmission in these cars? Is this something a competent DIYer can tackle at home, or is it strictly a dealer job due to special tools or procedures?

Any advice or experiences with this would be greatly appreciated!

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 4:19 AM

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ClearTheCode guidance (Mercedes-Benz · Maintenance & DIY)

Summary: For 2017 C300 Transmission Service - Rough Shifts After 60k Miles, 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,

My 2017 C300 (W205) with about 65,000 miles has started shifting a bit rough, especially from 2nd to 3rd gear. It's not terrible, but definitely noticeable compared to how smooth it used to be. I'm wondering if it's time for a transmission fluid and filter change.

I remember the dealer mentioning it's a "lifetime" fluid, but I've heard from independent shops that's not really the c…

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

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