2021 Ram 2500: Power Train complaints
Owner-reported issue (NHTSA complaints, not a recall)
Symptoms
NHTSA has 25 owner complaints for the 2021 Ram 2500 that list the power train component. Complaints are individual owner reports, not verified defects.
Examples:
- NHTSA complaint ODI #11763494 (filed 09/10/2026): “I am writing to formally follow up regarding complaint/case number 97989810 through dodge and to request that this matter be elevated for a complete technical review concerning my 2021 ram 2500 6.7l cummins, vin [xxx]. time - line prior factory-warranty repair the xxx factory-warranty repair is an…”
- NHTSA complaint ODI #11762597 (filed 09/07/2026): “There is a known issue with the ram power wagon locking differential system where the electronic locking differential wiring harness will fault one of three ways. the first being that the wiring harness is two short so when the rear axle articulates there isn't enough slack therefore causing the plu…”
- NHTSA complaint ODI #11734218 (filed 04/28/2026): “The 68rfe automatic transmission in this 2021 ram 2500 6.7l cummins fails to engage reverse when the transmission reaches operating temperature. when the gear selector is placed in reverse and the accelerator is applied, the engine revs but the truck does not move. the defect is intermittent and tem…”
Likely causes
These complaints do not establish a single root cause; read the examples above and get a diagnosis.
Fix, in plain English
No single fix is established by these reports. Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer about technical service bulletins (TSBs) or extended warranty coverage, then have the system diagnosed.
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 for this issue. Get a written quote after diagnosis.
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