One problem related to differential unit has been reported for the 2001 Subaru Forester. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 Subaru Forester based on all problems reported for the 2001 Forester.
1) grinding noise when accelerating especially going up hill. 2) 4wd differential failure 3) differential can only be replaced as part of the whole transmission. 4) vehicle only has 86300 miles, seems like a transmission/differential should last longer than that. Cost for replacement over $3,700.