LS400 & SC400
- Disconnect negative battery cable. Remove engine undercover. Drain coolant. Remove battery cover, air cleaner cover and air cleaner hose. Remove battery. Remove relay box cover, air cleaner and throttle body cover. Disconnect control cables from throttle body.
- Remove intake air connector (tube between throttle body and air cleaner). Remove wiring covers from engine. Remove right timing belt cover No. 3. Remove left timing belt cover No. 3. Remove throttle body. Remove spark plug wires and spark plugs. Remove cylinder head covers.
- Rotate crankshaft clockwise until cylinder No. 1 is at TDC of compression stroke. Groove on crankshaft pulley should be aligned with "0" timing mark on timing belt cover, and timing marks on camshaft pulleys should be aligned with timing marks on timing belt rear plates.
- Measure and record clearance of intake valves for cylinders No. 1, 2, 5, 7 and 8, and exhaust valves for cylinders No. 1, 4 and 8. See Fig 1 and Fig 2. Rotate crankshaft 360 degrees. Measure and record clearance of intake valves for cylinders No. 3, 4 and 6, and exhaust valves for cylinders No. 2, 3, 5, 6 and 7.
- Compare actual clearance with specified clearance. See VALVE CLEARANCE SPECIFICATIONS (LS400 & SC400) table. If clearance is within specification, go to step 9). If clearance is not within specification, rotate crankshaft until camshaft lobe of valve to be adjusted is facing upward, away from lifter shim.VALVE CLEARANCE SPECIFICATIONS
Application (1) In. (mm) Exhaust .010-.014 (.25-.35) Intake .006-.010 (.15-.25) (1) Adjust valves with engine cold. - Rotate adjustment shim until notch is at a 90-degree angle to camshaft (perpendicular), facing spark plug. Using Valve Lifter Press (SST 09248-05011), press valve lifter downward. See Figure. Install Valve Lifter Stopper (SST 09248-05021) between camshaft and valve lifter. Remove valve lifter press. Using compressed air and magnet, remove adjusting shim by blowing air into shim hole.
- Using a micrometer, measure thickness of shim removed. Replace removed shim with a shim of different thickness to bring valve clearance to specification. See VALVE CLEARANCE SPECIFICATIONS (LS400 & SC400) table.
- Shims are available in thicknesses of .0984-.1299" (2.50-3.30 mm), in increments of .002" (.05 mm). To install shim, press downward on valve lifter using valve lifter press. Remove valve lifter stopper. Recheck valve clearance after shim is installed.
- To complete installation, reverse removal procedure. Use NEW gaskets as necessary. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS TABLE at the end of this article.