Camshaft: Testing and Inspection

1ZZ-FE ENGINE MECHANICAL: CAMSHAFT:

INSPECTION

1. INSPECT CAMSHAFT TIMING GEAR ASSEMBLY





(a) Check the lock of the camshaft timing gear.
(1) Clamp the camshaft in a vise, then confirm that the camshaft timing gear is locked.

NOTE: Be careful not to damage the camshaft.

(b) Release the lock pin.
(1) Cover the 4 oil paths of the cam journal with vinyl tape as shown in the illustration.

HINT: Two advance side paths are provided in the groove of the camshaft. Plug one of the paths with a piece of rubber.

(2) Puncture the tape over the advance side path and retard side path on the opposite side of the groove.





(3) Apply air pressure to the two broken paths (the advance side path and retard side path) of about 150 kPa (1.5 kgf/cm2).

CAUTION: Cover the paths with a shop rag to avoid oil splashes.





(4) Confirm that the camshaft timing gear revolves in the timing advance direction when weakening the air pressure of the timing retard path.

HINT: The lock pin is released, and the camshaft timing gear revolves in the advance direction.

(5) When the camshaft timing gear comes to the most advanced position, release the air pressure of the timing retard side path, then release that of the timing advance side path.

CAUTION: The camshaft timing gear occasionally shifts to the retard side abruptly if the air compression of the advance side path is released before the retard side path. This often causes the breakage of the lock pin.

(c) Check the smooth revolution.
(1) Revolve the camshaft timing gear several times within the movable range except for the most retarded position and check that it turns smoothly.

CAUTION: Be sure to perform this check by hand, instead of using air pressure.

(d) Check that the lock is in the most retarded position.
(1) Confirm that the camshaft timing gear is locked in the most retarded position.
2. REMOVE CAMSHAFT TIMING GEAR ASSEMBLY





(a) Clamp the camshaft in a vise, then confirm that the camshaft timing gear is locked.

CAUTION: Be careful not to damage the camshaft.

(b) Cover the 4 oil paths of the cam journal with vinyl tape as shown in the illustration.

HINT: Two advance side paths are provided in the groove of the camshaft. Plug one of the paths with a piece of rubber.

(c) Puncture the tape over the advance side path and retard side path on the opposite side of the groove.





(d) Apply air pressure to the two broken paths (the advance side path and retard side path) of about 150 kPa (1.5 kgf/cm2).

CAUTION: Cover the paths with a shop rag to avoid oil splashes.





(e) Confirm that the camshaft timing gear revolves in the timing advance direction when weakening the air pressure of the timing retard path.

HINT: The lock pin is released, and the camshaft timing gear revolves in the advance direction.

(f) When the camshaft timing gear comes to the most advanced position, release the air pressure of the timing retard side path, then release that of the timing advance side path.

CAUTION: The camshaft timing gear occasionally shifts to the retard side abruptly if the air compression of the advance side path is released before the retard side paths. This often causes the breakage of the lock pin.





(g) Remove the fringe bolt and camshaft timing gear.

- Be sure not to remove the other 4 bolts.
- When reusing the camshaft timing gear, release the straight pin locking first, then install the gear.