(Reuters) -The U.S. Office of Defect Investigations (ODI) has opened a preliminary evaluation of a failure of the K1 snap ring in Chrysler-parent Stellantis' ( STLA ) year 2022 RAM 3500, 4500, and 5500 trucks, the National Highway Traffic Safety Administration (NHTSA) said on Friday.

The ODI has received 82 complaints alleging loss of motive power due to an internal transmission failure of the K1 snap ring, the NHTSA said.

Of these complaints, 16 describe a complete loss of motive power at speeds greater than 25 miles per hour, without the ability for the vehicle to resume normal operation, the NHTSA said.

The snap ring becomes dislodged and forward gears 1 to 4 are no longer functional during a failure, potentially leaving the vehicle disabled.

According to the NHTSA, the company's U.S. unit FCA has conducted some testing and said that during such an event a warning message will display to the operator, and gear 5 and reverse will remain available.

(Reporting by Arsheeya Bajwa in Bengaluru; Editing by Kirsten Donovan and Mrigank Dhaniwala)