Timing chain and sprockets [Toyota RAV4 XA10]

Removal

Remove the chain on a cold engine in the following order:

• turn off the ignition and disconnect the ground wire from the battery;
• remove the accessory drive belt;
• remove the generator;
• remove the cylinder head cover;
• if present, remove the ABS unit;
• apply the parking brake and block the rear wheels with chocks;
• loosen the right front wheel mounting nuts. Raise the front of the vehicle and place it on supports. Remove the right front wheel and the right front wheel arch mudguard;
• drain the coolant;
• unscrew the bolts, remove and set aside the power steering pump with the hoses connected to it. Secure the pump to the body with soft wire;

• set the piston of the first cylinder to TDC in the compression stroke, while the mark on the vibration damper should be aligned with the TDC or 0 sign on the front chain cover (see fig. 3.52), and the marks on the camshaft sprockets must be aligned with the marks on the camshaft bearing caps (Fig. 3.55);

• remove the pulley/vibration damper from the crankshaft, but do not turn the crankshaft. If the crankshaft does turn, return it to the position corresponding to the installation of the piston of the first cylinder at TDC in the compression stroke;
• using a jack, lift the engine through a wooden block installed under the oil pan so that its weight is supported by the jack.
• remove the left engine mount;

• remove the chain tensioner (Fig. 3.56) and the crankshaft angle sensor from the front chain cover. Unscrew the bolt securing the crankshaft angle sensor wiring harness to the chain cover;
• remove the oil pan;
• remove the bolts and the wiring harness holder from the timing chain cover;

• unscrew the nuts (Fig. 3.57) and remove the chain tensioner from the rear side of the cover;

• remove the bolts (fig. 3.58, 3.59) and use a pry bar to separate and remove the chain cover from the cylinder block. Mark the location of the bolts, as they are different lengths;
• remove the crankshaft angle sensor;

• unscrew bolts 1,3 (Fig. 3.60) and remove tensioner 2 and lower chain guide 5;
• remove the chain from the camshaft sprockets and the sprocket and chain from the crankshaft. If the chain is to be reinstalled, mark the front side of the chain with chalk, marker or paint. If the chain rotates in the opposite direction during installation, due to the existing wear on the chain, the wear on the timing mechanism components will increase and the noise generated by the chain will increase;
• remove the fixed chain guide 4;

• holding the camshaft from turning with a wrench by the hexagon, unscrew the mounting bolt and remove the sprocket from the camshaft (Fig. 3.61).

Caution! In addition to the sprocket, the intake camshaft also contains the variable valve timing (VVT) pulley/drive assembly. When removing the intake camshaft sprocket, remove only the center VVT pulley/drive mounting bolt. Do not remove the 4 VVT pulley/drive mounting bolts to the sprocket.

Examination

Visually inspect the components for wear and damage. Check the chain links for cracks, wear on the rollers and side plates. Check the condition of the sprocket teeth, which should be symmetrical. Tighten the chain and measure the distance between 8 chain links, which should be 122.6 mm (Fig. 3.62). Perform this check on several sections of the chain. If the chain has lengthened, replace the chain and sprockets as a set.



Wrap each sprocket with chain and measure the sprocket diameter across the chain rollers (Fig. 3.63). If the resulting measurement exceeds the minimum chain diameter, replace the chain and sprockets as a set.





Check the chain guides for excessive wear. Note that minor wear on the guides is normal. The depth of the grooves on the chain guides should not exceed 1.0 mm (Fig. 3.64). If excessive wear is present, check the chain guide oil hole on the front side of the cylinder block for dirt and clogging (see fig. 3.95).

Installation

Perform installation in the following order:

1) Use a scraper to remove the remains of the old sealant from the mating surfaces of the chain cover and the cylinder head and block;

2) Make sure that the camshafts are turned with the dowel pins upwards, in the "12 o'clock" position, then install both sprockets, aligning the pin hole on the back of the sprocket with the camshaft pin. Apply a locking compound to the threads of the sprocket mounting bolts to prevent them from loosening, and screw the bolts in by hand. Holding the camshaft with a wrench from turning by the hexagon, tighten the sprocket mounting bolt to a torque of 54 N·m (see fig. 3.61);

3) if necessary, turn the camshafts to a position where the marks on the camshaft sprockets are aligned with the marks on the camshaft bearing caps (see fig. 3.55);

4) If the crankshaft has been turned from the TDC position, turn it to a position where the keyway is not facing upwards, to the "12 o'clock" position;

5) install the fixed chain guide 4 (see fig. 3.60);

6) Put the chain on the crankshaft sprocket, aligning the color mark #1 on the chain with the mark on the sprocket. Install the sprocket with the chain installed on it onto the crankshaft, then install the lower chain guide;

Please note! There are three colored marks on the chain. Mark #1 is located at a greater distance from the other two marks, which are located close to each other.

7) Install the chain on the fixed chain guide shoe, then on the exhaust camshaft sprocket and finally on the intake camshaft sprocket. Check that the color marks on the chain are aligned with the marks on the sprockets (Fig. 3.65). When installing the chain, eliminate sagging of the right chain branch;



8) remove the slack from the left chain branch, install the chain tensioner, screw in the pivot bolt and tighten it to 19 Nm. After installation, make sure that the protrusion on the tensioner mechanism (Fig. 3.66) does not pass the stop against the cylinder head;

9) re-check that the piston of the first cylinder is at TDC in the compression stroke, while the mark on the vibration damper should be aligned with the TDC sign or 0 on the front chain cover (see fig. 3.52), and the marks on the camshaft sprockets must be aligned with the marks on the camshaft bearing caps (see fig. 3.55);

10) install the crankshaft angle sensor and the ring, the F mark on which should be directed outward;



11) Apply a 3-4 mm layer of RTV sealant to the mating surfaces of chain cover 1 (Fig. 3.67). Also apply a small amount of sealant to the joints of the head and cylinder block. Install the cover on the engine and secure with bolts, setting them in their original positions. Gradually, in several passes, tighten the bolts to the required torque;



12) Set the chain tensioner plunger to its original position as follows:

• lift the ratchet pawl and push the plunger in until it reaches the lower limit (Fig. 3.68);
• hook the hook on the tensioner body onto the pin on the plunger, which will lock the plunger in its original position;

13) lubricate the sealing rings of the tensioner plunger with engine oil and install it in the chain cover;

14) Install the pulley/vibration damper on the crankshaft;



15) Turn the engine crankshaft slightly counterclockwise to set the chain tension. In this case, hook 1 (Fig. 3.69) on the tensioner housing should release from pin 2 on the plunger, causing the plunger to tension the chain. If the plunger does not release on its own, press the chain tensioner and release the pin on the plunger with a screwdriver blade;

16) Turn the engine crankshaft clockwise a few revolutions and set the piston of the first cylinder to TDC in the compression stroke. Check that the mark on the vibration damper is aligned with the TDC or 0 sign on the front chain cover (see fig. 3.52), and the marks on the camshaft sprockets are aligned with the marks on the camshaft bearing caps (see fig. 3.55).

Further installation is carried out in the reverse order of removal.