Page 55 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

• Loosen the lock-nut with a ring spanner.

• Insert a feeler gauge (1) of the specified thickness between the valve stem and the rocker tip (4).
• Tighten the adjusting screw (5) by a screwdriver (2) and at the same time move the feeler gauge to and fro.
• Stop tightening of the adjusting screw when the feeler gauge can be slid with a slight effort, but it should not
be jammed.
• Rotate the push-rod. It should also rotate with a slight load but it should not be jammed.
• Hold the adjusting screw in position with the screwdriver firmly and tighten the lock-nut by a ring spanner.
• Ensure that the adjusting screw does not turn while tightening the locking nut.

• Check again the adjustment by sliding the feeler gauge leaf in the gap and turning the push rod.
• Repeat the above steps to adjust the tappet clearance for other valves bringing the respective pistons on TDC
of compression stroke according to firing order.
• Follow the sequence of adjusting the remaining valves by referring to the tabulation below:

When the inlet valve in No.4 cylinder is fully open, No.1 cylinder inlet valve is fully closed - this
feature is useful to remember when checking valve clearances.

• Adjust No.1 valve when No.8 is lifted.
• Adjust No.2 valve when No.7 is lifted.
• Adjust No.3 valve when No.6 is lifted.
• Adjust No.4 valve when No.5 is lifted.

• Adjust No.5 valve when No.4 is lifted.
• Adjust No.6 valve when No.3 is lifted.
• Adjust No.7 valve when No.2 is lifted.
• Adjust No.8 valve when No.1 is lifted.
• For adjusting valve tappet clearance of an overhead valve with an overhead camshaft engine, repeat the
above steps correctly with the following precautions (Fig 3).

Precaution: Ensure that the rocker arm is off the camshaft cams. This is to be followed for each
valve adjustment.

• Start the engine and leave it in idle speed
• Check the tappet noise, if found noise adjust and rectify the noise.

38
CITS : Automotive - Mechanic Diesel - Exercise 2.15