How To Replace Subaru Timing Belt

This procedure is taken from the Subaru service manual and will be used as a reference only. We always recommend that a Subaru specialist carries out work. We have reworded it slightly to help understand it better. This covers All Subaru EJ Quad Cam Engines From 1998 Onwards.

Timing Belt kits for 1998 Onwards Quad cam models can be found here

REMOVAL
1) Remove the V-belt.
2) Remove the crankshaft pulley.
3) Remove Air Pump Only Applicable to 2007+ Models,
4) Remove the timing belt covers.
5) Remove the timing belt guides. The Guide over the crankshaft needs to be removed, The guides on the camshafts can be loosened and pulled back from the belt & tightened back up to give clearance between the belt & guide. (Manual Transmission Models Only)

6) Turn the crankshaft using either the crankshaft bolt or the ICP crankshaft Socket, and align the alignment marks on crankshaft sprocket, intake camshaft sprocket (LH), exhaust camshaft sprocket (LH), intake camshaft sprocket (RH) and exhaust camshaft sprocket (RH) with notches of timing belt cover and cylinder block. Once you have it timed up, before removing the timing belt, you can use the ICP Camshaft Locking Tool to lock the camshafts in place, this makes it much easier as the LH bank of cylinders are on the valve spring compression, so once the timing belt is removed the camshaft pulleys will move if our tool isn’t used.
7) Remove the bottom smooth plain idler bearing
8) Remove Timing Belt
9) Remove the top smooth plain idler
10) Remove the small smooth plain idler
11) Remove the toothed idler bolted to the water pump
12) Remove the automatic belt tensioner adjuster
13) Install the New Automatic Belt Tensioner adjuster. Tightening torque: 39 N·m (4.0 kgf-m, 28.9 ft-lb)
14) Install New toothed idler on the water pump. Tightening torque: 39 N·m (4.0 kgf-m, 28.9 ft-lb
15) Install New bottom smooth idler Do not tighten up yet, screw the bolt in 5 threads. This helps get the timing belt on all the pulleys
16) Install New top smooth idler. Tightening torque: 39 N·m (4.0 kgf-m, 28.9 ft-lb
17) Install New top small smooth idler. Tightening torque: 25 N·m (2.5 kgf-m, 18.1 ft-lb
18) Install New Timing Belt. All our timing belts come with timing marks printed on the belt to help with fitment. If you are fitting a belt without timing marks, please see the diagram below for the teeth count between timing marks.

19) Tighten bottom smooth idler Tightening torque: 39 N·m (4.0 kgf-m, 28.9 ft-lb
20) Make sure all the timing marks are correct and lined up. Remove the stopper pin from the tensioner adjuster
21) Turn over by hand 2 full rotations and make sure the timing marks on the crankshaft & camshaft pulleys are lined up. (don’t worry about the timing marks on the belt these will not line up again.
22) Fit Crankshaft sprocket timing belt guide, Clearance between belt and guide 1mm-1.5mm, Tightening torque: 10 N·m (1.0 kgf-m, 7.2 ft-lb)
23) Fit Camshaft Pulley Timing belt guides, Clearance between belt and guide 1mm-1.5mm, Tightening torque: 6.4 N·m (0.65 kgf-m, 4.7 ft-lb)
24) Fit timing Covers
25) Fit Air pump (Only Applicable to 2007+ Models)
26) Fit Crankshaft Pulley & Bolt
27) Fit V belts

THINGS TO KNOW
Improper clearance in the belt guides can lead to severe engine failure, so it’s crucial to ensure these clearances are set correctly. If the guides are positioned too closely to the timing belt, they may begin to rub against it. This friction can generate excessive heat, which then transfers to the tensioner bearing, leading to its premature failure. In cases where the rubbing continues, the belt itself could become shredded, resulting in significant damage.

When adjusting the belt guides, exercise extreme caution. Tightening one side of the guide will inevitably bring the opposite side closer to the belt, potentially worsening the clearance issue. After completing the adjustments, take the time to double-check the clearances of the guides to ensure they are within the correct specifications. Careful monitoring during this process is essential to prevent future complications.

Sponge state Automatic Belt Tensioner adjuster, this is when the oil & air mix in the tensioner during storage & shipping. This causes the tensioner to be soft and not tension correctly. Please see our full how-to on this for a more in-depth look.

Crankshaft Pulley Bolt Torque Settings. These are taken from NTN. Always check the Subaru service manual for torque settings to be 100% sure.
EJ20 1998 to 2000 tightening torque 122-137 Nm
EJ20 2000 To 2004 Lubricate the thread and the face of the bolt and tighten to 44 Nm. Then tighten the bolt to 127 Nm, checking the bolt rotates 45°; if this is not the case, remove the bolt and put in a new one. Tighten the bolt. Tightening torque: 44 Nm + 45-60°
EJ20 2005+ lubricate the thread and the face of the bolt and tighten to 44 Nm. Then tighten the bolt to 130 Nm, checking the bolt rotates 45°; if this is not the case, remove the bolt and put in a new one. Tighten the bolt. Tightening torque: 44 Nm + 45-60°
EJ25 2005 To 2007 lubricate the thread and the face of the bolt and tighten to 44 Nm. Then tighten the bolt to 180 Nm, checking the bolt rotates 65°; if this is not the case, remove the bolt and put in a new one. Lubricate the bolt threads. Tighten the bolt. Tightening torque: 44 Nm + 65-75°
EJ25 2007+ lubricate the thread and the face of the bolt and tighten to 44 Nm. Then tighten the bolt to 180 Nm, checking the bolt rotates 65°;
if this is not the case, remove the bolt and put in a new one. Lubricate the bolt threads. Tighten the bolt. Tightening torque: 44 Nm + 65-75°