DETROIT -- Federal safety regulators want to know why Chrysler Group has taken more than a year to begin fixing older-model Jeep Grand Cherokees and Libertys to improve their rear crashworthiness.
In June 2013, Chrysler reached a settlement with the National Highway Traffic Safety Administration and agreed to install trailer hitch assemblies on as many as 1.5 million 1993-98 Grand Cherokees and about a million 2002-07 Libertys. The assemblies are designed to protect the fuel tank.
A supplier contracted by Chrysler began manufacturing the hitch assemblies on May 14. Last week, NHTSA gave the automaker until July 16 to explain.
Under the automaker's current schedule, dealers will begin installing the assemblies in August.
Chrysler, in a response last week, defended its handling of the program and said NHTSA has been aware of its efforts throughout the process. Chrysler has contended that the vehicles are safe.
The safety agency also said it is concerned that the pace of production of the trailer hitch assemblies has been too slow to adequately meet demand for the vehicles that need to have them installed.
NHTSA said Chrysler "waited until December 6, 2013, to select a hitch supplier and did not issue a purchase order to the hitch supplier until January 29, 2014."
The agency said the supplier's rate of production means "it will take Chrysler at least 4.7 years and 2.06 years respectively to produce the required number of Grand Cherokee and Liberty hitches."
In a statement, Chrysler said it had to "find and enlist multiple new supplier partners to supply volume of this part that far exceeded normal demand" and that production has begun. It said suppliers had agreed to "a work schedule of three shifts per day, six days per week, with occasional Sunday production" to meet demand and that it would contact customers "when the time is appropriate to schedule service."