This bulletin applies to 2018 Jeep Grand Cherokee vehicles equipped with 4-wheel drive. A grinding noise may be heard from the front of the vehicle, mostly heard while in 4WD mode, and the 4WD may not be fully engaging.
Remove the front skid plate. Check to see if one of the front differential mounting bolts to the cradle is missing. If missing, install a new bolt P/N 06511930AA and tighten to 87 ft.-lbs.
Reinstall the front skid plate and road test.