How to Replace Idler Pulley 00-09 Subaru Outback
Difficulty: Intermediate · About 60 min · Subaru Outback
Replace the idler pulley on a 2000–2009 Subaru Outback by documenting the belt routing, removing the tensioner assembly, and restoring both drive belts.
Tools you will need
- 10mm socket
- 12mm socket and extensions
- Ratchet
- Flat blade screwdriver
Parts and supplies
- Idler pulley
Steps
Document and remove the serpentine belt
Remove the belt cover fastener and note the belt routing from the underhood diagram or a photo. Loosen the tensioner adjustment bolts and remove the serpentine belt.
Remove the tensioner and pulley
Loosen the A/C belt adjuster as needed and remove that belt. Unbolt the tensioner assembly, then remove the idler pulley from the assembly.
Install the replacement pulley
Fit the new pulley to the tensioner assembly and secure it to the vehicle. Confirm it spins freely and is aligned with the other pulleys.
Reinstall the belts
Route the A/C belt and serpentine belt according to the original diagram. Adjust belt tension to the vehicle's specification and tighten the adjuster fasteners.
Reinstall the cover and verify
Reinstall the belt shield and check that each belt is centered in its pulley grooves. Start the engine briefly and listen for noise or belt tracking issues.
Check your vehicle’s repair manual for exact specifications and fit.