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2021 Ram 2500 — Should You Buy One?

Typical asking price: $42,000–$72,000. There is 1 high-severity known issue you need to know before handing over a check.

Kestrel Take

A serious heavy-duty truck and the 6.7L Cummins diesel is one of the most legendary truck engines ever made. Get the Cummins or walk.

Known Issues for the 2021 Ram 2500

Ranked by wallet impact. These are documented, recurring problems — not freak accidents.

Aisin transmission shudder with Cummins (early builds)High — wallet impact

The Aisin 6-speed had documented shudder and harsh-shift issues on 2021 builds. TSBs addressed most cases.

Repair cost range: $0 software to $5,000 rebuild

DEF system errorsMedium

DEF sensor failures and heater issues trigger warning lights and can cause a speed-limiting limp mode if ignored.

Repair cost range: $200-$1,500

Walk-Away Red Flags

  • 6.4L Hemi for heavy towing — not built for the same workload as the Cummins
  • DEF warning lights active or contamination history

Good Signs

  • 6.7L Cummins diesel — one of the most reliable truck engines ever made
  • All transmission TSBs applied and documented
  • Clean DEF system

Found a specific Ram 2500?

This page covers what goes wrong on the 2021 Ram 2500 in general. The Kestrel report covers this specific car— the asking price vs. market, the photos, the seller's description, and a BUY / NEGOTIATE / WALK AWAY verdict with a negotiation script.

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Known issues on this page are based on documented owner reports, NHTSA complaints, class-action records, and manufacturer technical service bulletins. Individual vehicles vary. A pre-purchase inspection by a trusted mechanic is always worth doing.