Supplied by Allison Transmission of Indianapolis, the 2500RDS is normally used in the Class 7 FVR. It also doesn’t have a pawl by design. The 2550RDS intended for the Class 6 FTR does have a parking pawl, and the automatic transmission shift lever in these trucks has a park position.
How could this happen, you might be wondering? Isuzu discovered that its end-of-line dynamic vehicle test booth exhibited a software logic flaw, which failed to detect which transmission was installed in the subject vehicles. The software logic was corrected on March 23rd. Fast forward to May 20th, and Isuzu learned of a second Class 6 FTR cab-over truck in the field that was found to have rolled after the shift lever was placed in park.
The Japanese company reopened the investigation. After matching a list of VINs with transmission serial numbers, Isuzu then contacted Allison Transmission for additional help. The supplier’s investigation determined that a grand total of four vehicles had been produced with the wrong box.
The recall includes an FTR assigned with an incorrect serial number, an FTR currently owned by a dealership, and the vehicles that were subject to the aforementioned reports. Dealers have been instructed to replace the 2500RDS with the 2550RDS transmission. Owners will be notified by first-class mail on August 12th according to the NHTSA report attached below.