The 1996 Lexus ES300 has a freewheeling engine in which a timing belt failure is unlikely to do any damage to the engine. It will fail without warning if left unattended past the recommended replacement of 60,000 miles. Lexus has determined the time change for the belt after reviewing the previous service history. At 60,000 miles the timing belt tensioner is close to its limit of travel, making it unable to apply tension to the timing belt. As the belt continues to stretch, its teeth will no longer engage the crankshaft sprocket teeth.
Plug the battery saver into the cigarette lighter. Turn the ignition switch to the “Lock” position. Disconnect the battery ground cable using a wrench. Wait at least 90 seconds to start so that the air bag disarms.
Slide the drain pan under the radiator petcock. Loosen the petcock to drain the antifreeze. Remove the radiator cap to allow quicker draining. Dispose of the antifreeze in an appropriate manner. Most auto parts stores have a collection tank for used antifreeze.
Loosen the lug nuts on the right front wheel with the lug wrench. Do not remove them. Jack the front of the vehicle up with the floor jack. Support the vehicle on jack stands. Continue removing the front wheel. Remove the front fender apron seal using a socket. Remove the hoses from the coolant reservoir by loosening the clamps with a flat-head screwdriver. Remove the coolant reservoir using a socket.
Loosen the alternator pivot bolt with a socket. Loosen the adjusting lock bolt and the adjusting bolt with a socket. Turn the adjusting bolt until the belt has enough slack to remove it. Remove the belt. Loosen the power steering pump mounting bolts with a socket. Slide the power steering pump up to loosen tension on the belt. Remove the belt.
Place the 2-inch thick board on the floor jack. Slide the floor jack under the oil pan. Raise the jack so that it touches the oil pan. Remove the four bolts that attach the engine mount to the engine with a socket. Remove the bolts that attach the bottom of the mount to the crossmember. Remove the mount. Remove the mounting bolts for the engine movement control rod, or strut mount, with a socket. Remove the strut mount.
Unplug the alternator wiring harness connector with your fingers or a flat-head screwdriver. Remove the nut on the power wire with a wrench. Remove the power wire. Reinstall the nut so you don’t lose it. Disconnect the wire harness from the clip with your fingers. Remove the pivot bolt and adjusting lock bolt with a socket and ratchet. Remove the alternator. Remove the alternator bracket retaining bolts with a ratchet and socket. Remove the brackets.
Hold the crankshaft pulley with the holding tool and handle so it doesn’t turn. Remove the crankshaft pulley bolt using the socket and ratchet. Install the special puller on the crankshaft pulley and remove the pulley. Unbolt and remove the timing belt upper and lower covers with a socket.
Remove the timing belt guide plate on the crankshaft by sliding it off. Reinstall the crankshaft pulley bolt. Turn the crankshaft clockwise until the timing mark on the crankshaft pulley is lined up at the 1 o’clock position. The timing mark on the sprocket is a dot. The dot lines up with the raised timing mark at the 1 o’clock position on the block. Check the camshaft sprockets. The timing marks on both are at the 12 o’clock position, or vertical, and line up with the timing mark on the cylinder head. If the marks are not lined up, turn the crankshaft one more full rotation and all three marks will line up.
Match mark the belt at each sprocket timing mark. Mark the direction of rotation of the belt with the white marker. Remove the auto tensioner unit with a socket. Lift the timing belt off the sprockets.
Remove the camshaft sprockets. If the pulleys have lock tabs, carefully lift the lock tab up with a screwdriver. You may have to tap the handle of the screwdriver to get it under the lock tab. Remove the bolts and slide the sprockets off. Do not turn the camshafts while you are removing the sprockets.
Remove the idler pulley with a socket. Remove the rear timing cover with a socket. Remove the water pump bolts and nuts with a socket. Lift the water pump and gasket out of the vehicle. Clean the mating surfaces with a plastic scraper and shop rags.
Place a thin layer of RTV silicone on the mounting surface of the water pump. Let it set up for about two minutes. Stick the gasket onto the RTV and spread RTV on the engine side of the gasket also. Reinstall the water pump and torque the bolts and nuts to 69 inch-pounds. Reinstall the rear timing belt cover and tighten the bolts firmly. Install the idler pulley and torque it to 32 foot-pounds.
Install the right camshaft sprocket. Ensure the flange side is outward. Align the knock pin on the camshaft with the knock pin groove on the sprocket. Slide the sprocket into place. If the cams have lock tabs, slide the lock tab into place, then install and torque the bolt to 94 foot-pounds. Bend the lock tab over the top of the bolt. Repeat for the left camshaft sprocket.
Check the auto tensioner by removing the dust boot. Make sure the tensioner is not leaking oil. Replace it if it is. Push the tensioner against the wall. If the pushrod moves, replace the tensioner. Measure the pushrod protrusion with the veneer caliper. If it is not between 0.39 and 0.43 inches, replace it.
Push the pushrod into the tensioner with a vise. Line up the holes in the tensioner casing and the pushrod. Slide an Allen wrench in the hole to hold the pushrod in place. Reinstall the dust boot.
Make sure the timing marks are still lined up. Install the timing belt, making sure all the marks on the belt line up with the marks on the sprockets. Work in a counterclockwise direction. Start at the crankshaft sprocket, then route the belt behind the water pump, over the top of the right camshaft sprocket, under the idler over the top of the left camshaft sprocket and behind the tensioner. Keep tension on the non-tensioned side of the belt as you are installing it.
Install the auto tensioner and torque the bolts to 20 foot-pounds. Remove the Allen wrench. Allow the tensioner to put tension on the belt. Turn the crankshaft clockwise two turns until the timing marks line up again. Remove the crankshaft pulley bolt.
Reinstall the timing belt guide plate, the right engine mount, the timing covers, crankshaft pulley and crankshaft pulley bolt. Use the crankshaft pulley holding tool and handle to hold the crankshaft pulley. Torque the crankshaft bolt to 159 foot-pounds.
Reinstall the alternator bracket and alternator. Plug in the wiring harness connector and reinstall the power wire. Reinstall the accessory drive belts. Turn the adjusting bolt until the belt can be twisted 90 degrees. Snug the adjuster lock nut. Tighten the pivot bolt. Install the front lower motor mount to the engine and torque the bolts to 47 foot-pounds. Lower the engine and install the bolts in the motor mount bracket to the crossmember. Torque these bolts to 59 foot-pounds. Install the engine movement control rod and torque the bolts to 35 foot-pounds.
Install the inner splash shield. Install the tire/wheel assembly and torque the lug nuts to 217 foot-pounds. Install the coolant reservoir and hose. Raise the vehicle and remove the jack stands. Lower the vehicle.
Close the radiator petcock. Fill the radiator with 50-50 pre-mix Ethylene glycol base non-alcohol type antifreeze. Make sure the ignition is in the “Lock” position. Reinstall the negative battery cable. Remove the battery saver. Wait 90 seconds. Turn the ignition switch from the “Lock” position.
Start the vehicle and allow it to come to operating temperature. Check for leaks. Top off the radiator as needed after the thermostat opens. Install the radiator cap and fill the coolant reservoir tank as needed. Drive the car for a short period and recheck the coolant level.
