Timing Chain Removal Note
WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.
- Release the tension on the timing chain using the following procedure:NOTE:
- Release the tension on the timing chain by securing the timing chain tensioner arm through the service hole on the engine front cover.
- Rotate the crankshaft clockwise so that cylinder No. 1 is positioned around before top dead center (TDC) as shown in the illustration.NOTE:
- With cylinder No. 1 positioned around before top dead center (TDC), there is no large movement (rotation) of the exhaust camshaft when the timing chain is removed. Therefore, installation of the electric variable valve timing actuator to the camshaft will be easier. (If there is a large movement of the exhaust camshaft, installation of the electric variable valve timing actuator to the camshaft must be performed while loosening the chain by rotating the exhaust camshaft.)
- Remove the blind plugs (upper and lower) on the engine front cover service holes.
- Assemble several washers and a nut to an M6 bolt (35-60 mm {1.4-2.3 in}), entirely threaded type as shown in the illustration.CAUTION:
- If the thread area exceeds the length shown in the illustration, the tensioner arm could be damaged when fixing it. Adjust the number of washers so that the thread area does not exceed the length shown in the illustration.
NOTE:- Hold the exhaust camshaft using a wrench on the cast hexagon and move it back and forth a few times as shown in the illustration. This will drain the oil from the chain tensioner and make the following servicing easier.
- Insert a precision screwdriver into the lower service hole.
- While moving the exhaust camshaft back and forth in the direction of the arrow using a wrench on the cast hexagon, press down the link plate of the timing chain tensioner using a precision screwdriver and release the plunger lock.NOTE:
- When moving the exhaust camshaft back and forth, the timing chain pushes the plunger in the chain tensioner making it easier to operate the link plate.
- With the plunger lock released, rotate the exhaust camshaft clockwise until the timing chain loosens.
- With the chain loosened, screw the bolt prepared in Step 3 into the upper service hole by hand until the nut is seated and the tensioner arm is fixed.NOTE:
- If the bolt cannot be screwed-in until the nut is seated or if resistance can be felt when screwing-in the bolt, the tensioner arm could be damaged by the bolt. Because it is possible that the plunger lock of the chain tensioner cannot be released or there is a lack of chain looseness, remove the bolt and repeat the procedure from Step 4.
- When the exhaust camshaft is rotated clockwise, the tensioner arm is pressed by the dynamic chain and moved outside of the engine. When the bolt is screwed in under this condition, the bolt end contacts the inside of the tensioner rib, fixing the tensioner arm and releasing the tension on the chain.
- If the bolt cannot be screwed-in until the nut is seated or if resistance can be felt when screwing-in the bolt, the tensioner arm could be damaged by the bolt. Because it is possible that the plunger lock of the chain tensioner cannot be released or there is a lack of chain looseness, remove the bolt and repeat the procedure from Step 4.
- After securing the tensioner arm, remove the chain guide (No. 1).