This bulletin applies to 2004-2017 Toyota 4Runner, 2007-2014 FJ Cruiser and 2005-2015 Tacoma vehicles, all with 4WD.
Some vehicles may experience a cyclical groaning or grinding noise coming from the front differential in 2WD that goes away when in 4WD. This noise can be addressed by replacing the needle bearing on the left side of the front differential.
Remove the LH front driveshaft assembly. Remove the LH differential oil seal. Install a steering worm bearing puller onto the left side of the differential carrier assembly.
Note: The drive shaft may rotate during bearing removal. In this event, grab the driveshaft to prevent further rotation. Remove the LH differential needle bearing roller using the puller. Install a new needle bearing roller using the appropriate SSTs (refer to the service manual). Use a rubber-ended mallet to press the new part into the differential. Be sure to install the needle bearing roller with the engraved print facing outward. Pay attention to the installed depth at the outer surface of the roller should be 1.4 to 1.7mm. Replace the LH differential oil seal. Install a snap ring onto the front drive shaft and install the LH front driveshaft.
Use the SST handle and a rubber mallet to press the bearing into place. (left). Make sure that the engraved side of the bearing faces outward (center). The installed depth between surfaces 3A and 3B is 1.4 to 1.7 mm (right).