Serpentine belt replacement Guide2010 Subaru Forester
Complete DIY repair guide with step-by-step instructions. Find exact parts on Amazon for your vehicle.
Difficulty
Easy to Intermediate
Time
20-30 minutes
Parts Needed
1 items
DIY Savings
$100-400+
2010 Subaru Forester — What You Need to Know
- →EJ25 is a horizontally-opposed (boxer) engine — belt routing is horizontal instead of vertical. Allow extra time to understand layout
- →SEPARATE timing belt: EJ25 uses a rubber timing belt with a 105,000-mile replacement interval — do not confuse with serpentine belt
- →If timing belt has not been replaced at 105k miles, do this service at the same time as serpentine belt — saves significant labor
- →2006+ Forester models: verify you have 2.5L naturally aspirated EJ253, not the turbo EJ255 — turbo model has slightly different belt routing
Torque Specs
Tensioner bolt: 19 ft-lbs
Belt Routing
EJ25 boxer: Crankshaft → AC compressor → alternator → power steering pump → tensioner → idler. Belt runs horizontally due to boxer engine orientation.
Safety Warnings
- •Subaru EJ25 is a BOXER (horizontally-opposed) engine — components are sideways vs. upright. Belt runs left-to-right
- •The EJ25 also has a TIMING BELT (not chain) — check its replacement interval (105,000 miles). The serpentine is separate
Tools Required
12mm socket (tensioner)
Flashlight (engine is horizontal — unusual layout)
Parts Needed
Serpentine Belt6 rib — drives AC, alternator, PS pump (EJ25 horizontally-opposed engine)
Shop on AmazonGates K060895
Basic Procedure Overview
- 1Locate automatic spring tensioner on driver side of engine
- 2Rotate tensioner clockwise with 12mm socket to release tension
- 3Remove belt carefully — boxer layout means pulleys are at unusual angles
- 4Route new belt: crankshaft → AC → alternator → PS pump → tensioner → idler
- 5Release tensioner, verify belt tracking on all pulleys
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