This bulletin applies to 2004-2009 and 2010-2015 Toyota 4Runner vehicles equipped with part time 4WD. A cyclical groaning/grinding noise may be heard at the front differential when in 2WD that goes away when placed in 4WD. This noise can be addressed by replacing the needle bearing on the left side of the front differential, using P/N 90364-35008.
Remove the LH front drive shaft assembly. Remove the LH differential oil seal. Install a steering worm bearing puller on the left side of the differential carrier. Note that the drive shaft may rotate during bearing removal, so grab the drive shaft to prevent rotation. Remove the LH differential needle bearing roller using the steering worm bearing puller. Install the new needle bearing roller using SST 09950-70010-01. Install the new needle bearing roller with the engraved print facing outward. Use a rubber-ended mallet to press the new bearing into the differential. Installation depth should be 1.4 to 1.7mm.
Replace the LH differential oil seal using a new seal. Install the snap ring onto the drive shaft and install the drive shaft.