Download 2003 Lexus GS 300 Timing Belt Installation – Installation 1. Install idler pulley and plate washer (if removed). Apply Loctite 242 or equivalent on threads of idler pulley pivot bolt. Install and tighten bolt to specification. See TORQUE SPECIFICATIONS . Ensure idler pulley is clean and rotates smoothly, and idler pulley bracket moves freely. NOTE: The engine should be cold before adjusting timing marks. CAUTION: If reusing timing belt, ensure reference marks on timing belt and crankshaft timing pulley align, and timing belt is installed in original direction of rotation. 2. Using crankshaft pulley bolt, rotate crankshaft and align timing mark on crankshaft timing pulley with timing mark on oil pump body. See Fig. 3 , STEP 3. Clean oil or water off of crankshaft timing pulley, and install timing belt on crankshaft timing pulley and around idler pulley. 3. Install timing belt guide with cupped side away from crankshaft timing pulley and flat side against timing belt. Install gasket and No. 1 timing belt cover. Align crankshaft pulley key groove with crankshaft key. Install crankshaft pulley. 4. Ensure sub-timing mark (60 degrees BTDC) of crankshaft pulley is aligned with “0″ timing mark of No. 1 timing belt cover. See Fig. 3 , STEP 4. Temporarily install crankshaft pulley bolt. 5. If necessary, use spanner wrench to rotate camshaft timing pulleys so timing marks on camshaft timing pulleys align with timing marks on No. 4 timing belt cover. See Fig. 2 . Install timing belt on camshaft timing pulleys. Ensure tension exists on timing belt between camshaft timing pulleys.