Impreza 2.5 RS Sedan AWD F4-2.5L SOHC (2002)
7. Install the crankshaft pulley.
8. Install the V-belt.
DISASSEMBLY
1. Remove the bolts which secure the rocker shaft.
2. Extract the rocker shaft. Remove the valve rocker arms, springs and shaft supports from rocker shaft.
CAUTION: Arrange all removed parts in order so that they can be installed in their original positions.
3. Remove the nut and adjuster screw from valve rocker.
ASSEMBLY
1. Install the adjuster screw and nut to valve rocker.
2. Arrange the valve rocker arms, springs and shaft supports in assembly order and insert the valve rocker shaft.
Tightening torque (Shaft supports installing bolts): 5 Nm (0.5 kgf-m, 3.6 ft. lbs.)
CAUTION: Valve rocker arms, rocker shaft and shaft supports have identification marks. Ensure the parts with same markings are properly
assembled.
3. Install the valve rocker shaft securing bolts.
INSPECTION
1. VALVE ROCKER ARM
1 of 2
2 of 2
1. Measure the inside diameter of valve rocker arm and outside diameter of valve rocker shaft, and determine the difference between the two (=
oil clearance).
Clearance between arm and shaft:
Standard: 0.020 - 0.054 mm (0.0008 - 0.0021 inch)
Limit: 0.10 mm (0.0039 inch)
2. If the oil clearance exceeds the limit, replace the valve rocker arm or shaft, whichever shows greater amount of wear.
Rocker arm inside diameter: 22.020 - 22.041 mm (0.8669 - 0.8678 inch)
Rocker shaft diameter: 21.987 - 22.000 mm (0.8656 - 0.8661 inch)
3. Measure the inside diameter of rocker shaft support and outside diameter of valve rocker shaft, and determine the difference between the two
(= oil clearance).
Clearance between support and shaft:
Standard: 0.005 - 0.039 mm (0.0002 - 0.0015 inch)
Limit: 0.05 mm (0.0020 inch)
4. If the oil clearance exceeds the limit, replace the rocker shaft support or shaft, whichever shows greater amount of wear.
Rocker shaft support inside diameter: 22.005 - 22.026 mm (0.8663 - 0.8672 inch)
Rocker shaft diameter: 21.987 - 22.000 mm (0.8656 - 0.8661 inch)
