INSPECTION


ROCKER ARM SHAFT
Check the rocker arm mounting areas of the rocker arm shafts for wear or damage. Replace as necessary.

ROCKER ARM
1.Check the roller surface and replace the rocker arm if recesses, damage or heat seizure is observed.
2.Check roller rotation and replace the rocker arm if uneven rotation or roller backlash of the roller is observed.
3.Check the inside diameter and replace the rocker arm if damage or seizure is observed.

CAMSHAFT
1.Check the camshaft bearing journals for damage and binding. If the journals are binding, check the cylinder head for damage. Also check the cylinder head for clogged oil holes.


2.Check the cam surface for abnormal wear and damage and replace if necessary. Also measure the cam height and replace if out of minimum limit.

 Standard value
 Minimum limit
A: Intake low speed cam
 36.228 mm
 35.728 mm
B: Intake high speed cam
 37.209 mm
 36.709 mm
C: Exhaust cam
 37.874 mm
 37.374 mm

LASH ADJUSTERS

caution
  • The lash adjusters are precision-engineered mechanisms. Do not allow them to become contaminated by dirt or other foreign substances.
  • Do not attempt to disassemble the lash adjusters.
  • Use only fresh diesel fuel to clean the lash adjusters.
1.Prepare three containers and approximately 5 dm3 of diesel fuel. Into each container, pour enough diesel fuel to completely cover a lash adjuster when it is standing upright. Then, perform the following steps with each lash adjuster.

2.Place the lash adjuster in container A and clean its outside surface.
note Use a nylon brush if deposits are hard to remove.

3.
caution The steel ball spring is extremely weak, so the lash adjuster’s functionality may be lost if the air bleed wire is pushed in hard.
While gently pushing down the internal steel ball using wire (0.5 mm in diameter) or special tool Air bleed wire (MD998442), move the plunger through five to ten strokes until it slides smoothly. In addition to eliminating stiffness in the plunger, this operation will remove dirty oil.
note If the plunger remains stiff or the mechanism appears otherwise abnormal, replace the lash adjuster.

4.Remove the lash adjuster from the container. Then, push down the steel ball gently and push the plunger to eliminate diesel fuel from the pressure chamber.

5.
caution The steel ball spring is extremely weak, so the lash adjuster’s functionality may be lost if the air bleed wire is pushed in hard.
Place the lash adjuster in container B. Then, gently push down the internal steel ball using a wire (0.5 mm in diameter) or special tool Air bleed wire (MD998442) and move the plunger through five to ten strokes until it slides smoothly. This operation will clean the lash adjuster’s pressure chamber.

6.Remove the lash adjuster from the container. Then, push down the steel ball gently and push the plunger to eliminate diesel fuel from the pressure chamber.

7.
caution Do not use container C for cleaning. If cleaning is performed in container C, foreign matter could enter the pressure chamber when the chamber is filled with diesel fuel.
Place the lash adjuster in container C. Then, gently push down the internal steel ball using a wire (0.5 in diameter) or special tool Air bleed wire (MD998442).

8.Stand the lash adjuster with its plunger at the top, then push the plunger downward firmly until it moves through its greatest possible stroke. Return the plunger slowly, then release the steel ball and allow the pressure chamber to fill with diesel fuel.

9.Remove the lash adjuster from the container, then stand the lash adjuster with its plunger at the top. Push the plunger firmly and check that it does not move.
note If the lash adjuster contracts or moves, perform the operations 7 through 9 again to fill it with diesel fuel completely. Replace the lash adjuster if it still contracts or moves after performing these steps.
10.Stand the lash adjuster upright to prevent diesel fuel from spilling out. Do not allow the lash adjuster to become contaminated by dirt or other foreign matter. Fit the lash adjuster onto the engine as soon as possible.