OEM 2003 Toyota 4Runner Camshaft

2003 Toyota 4Runner Parts Questions & Experts Answers

• Q: How to replace the camshaft (RH) on 2003 Toyota 4Runner?

  A: To replace the camshaft (RH), begin by draining the engine coolant and removing the V-bank cover, followed by disconnecting ventilation hose No.2, removing the air cleaner assembly, and taking out the intake air surge tank by disconnecting the two water by-pass hoses, fuel vapor feed hose, ventilation hose, two VSV connectors, and throttle body w/motor connector, then separating the three wire harness clamps and hose clamp, removing the two bolts and throttle body bracket, the bolt and oil baffle plate, the four bolts and two surge tank stays, and the two nuts, before using a socket hexagon wrench 8 to remove the four bolts, intake air surge tank, and gasket. The servicing process starts with taking apart ten bolts, three seal washers and two nuts, cylinder head cover and gasket. The user then must repeat the process for cylinder head cover sub-assembly LH. Set No. 1 cylinder at TDC compression stage by rotating the crankshaft pulley until its notch matches the timing mark "0" on the timing chain cover while both camshaft timing gears should align with bearing cap marks. If realignment is needed, complete a full crankshaft rotation. Mark the No. 1 chain links which correspond to the camshaft timing gears. Disassemble chain tensioner assembly No.1 while avoiding crankshaft rotation and elevate the stopper plate while pushing the plunger in, then tightly fix the stopper plate to a 3.5 mm bar till you can remove the two bolts and tensioner piece. The first step to extract the No.2 camshaft involves keeping it horizontal to prevent any damage before elevating chain tensioner No.2 and using a 1.0mm pin to maintain its position while using a wrench to grip the No.2 hexagonal shaft portion and removing the camshaft timing gear set bolt then separating the timing gear by rotating the camshaft clockwise until the cam lobes of the first cylinder point upward and following a specified order to evenly loosen and remove the eight bearing cap bolts followed by removing both the four bearing caps and the No.2 camshaft. Fulfill the removal of chain tensioner assembly No.2 by disassembling the bolt followed by removal of the assembly. For No.1 camshaft removal, keep it level, hold the hexagonal portion with a wrench, loosen the timing gear set bolt, slide the timing gear, rotate the camshaft counterclockwise until the cam lobes face downward, loosen and remove the eight bearing cap bolts in the specified sequence, remove the four bearing caps, and then remove the timing gear set bolt while lifting the camshaft, followed by removing the No. 1 camshaft and timing gear with No. 2 chain, tying the No. 1 chain with a string to prevent dropping anything inside the timing chain cover. To install the camshaft, align the mark link (yellow) with the timing mark (1 dot mark) of the timing gear, apply new engine oil to the thrust portion and journal, temporarily place the No. 1 chain on the No. 2 chain, align the knock pin hole with the No. 1 camshaft, insert it into the timing gear, temporarily install the timing gear set bolt, set the No. 1 camshaft onto the RH cylinder head with the cam lobes facing downward, install the four bearing caps, apply a light coat of engine oil on the threads and under the heads of the bearing cap bolts, and uniformly install and tighten the eight bearing cap bolts in the specified sequence with the appropriate torque values. To properly set the timing mark between the timing gear and bearing caps users should rotate the No. 1 camshaft clockwise before aligning the paint mark of the chain with the timing mark while holding the hexagonal portion with a wrench then tighten the timing gear set bolt to the correct torque value. Insert a 1.0 mm pin then push in the tensioner before temporarily mounting both timing gear and tensioner yet keep the mark links correctly aligned to the timing marks and finally fasten tenseiring bolt to factory specifications. Begin the No.2 camshaft installation procedure by placing the cam shaft on top of the RH cylinder head with upward-facing cam lobes and continue by installing the four bearing caps followed by engine oil application to threads and under bearing cap bolt heads before performing uniform and torquing bolt installation according to specified values. Align the knock pin of No. 2 camshaft clockwise to face the timing gear then use a wrench to hold the hexagonal portion while installing the timing gear set bolt at proper torque before extracting the pin from the chain tensioner No. 2. The installation process of chain tensioner assembly No.1 includes turning the stopper plate clockwise then driving the plunger into position followed by fixing the stopper plate with a 3.5 mm bar while tightening the tensioner using the specified torque values before removing the bar and finally installing a new gasket together with the timing chain cover plate with four bolts at specified tightness values. Ot the crankshaft pulley as many times until the notch points to timing mark "0" then validate the camshaft timing gear positions against the surface of bearing caps. Align No. 1 cylinder at TDC compression to inspect valve clearance then adjust it for installation of the left hand cylinder head cover assembly by using packing removal and new packing (Part No. 08826-00080 or equivalent) within a three-minute period before adding seal washers and applying ten bolts and two nuts to correct torque settings. First install the ignition coil assembly to the specified torque then place the intake air surge tank with its new gasket by securing it with a socket hexagon wrench 8 through four bolts and two nuts to the specified torque while installing surge tank stays, oil baffle plate, throttle body bracket, and reconnecting all hoses and connectors. To finalize, install the air cleaner assembly while connecting ventilation hose No.2 then add engine coolant before checking for leaks and installing the two V-bank cover nuts according to specified torque specifications. The last step entails inspection of ignition timing using tool 09843 - 18040.