If the transmission delays initial gear engagement after being parked overnight or longer, it may be due to a suspect transmission cooler return filter. If the transmission was recently serviced and the part number for the cooler return filter contains an "AB" suffix at the end, a new filter should be installed.
Car Problem Reports
Jeep Grand Cherokee Replace Transmission Cooler Return Filter if it Has "AB" Suffix At End
Jeep Grand Cherokee Problem
Drive Trains Affected: 2WD, 4WD
Average Mileage: 64,000 mi (41,000 mi - 76,000 mi)