Doosan DE12T - Rocker Arm Shaft Assembly; Rocker Arm Shaft Diameter; Rocker Arm Shaft Run-Out; Valve Spring Tension

•
Valve spring tension
Use a spring tester to measure the valve
spring tension if the measured value is
less than the specified limit, the valve
spring must be replaced.
9.2.4. Rocker arm shaft assembly
1) Rocker arm shaft
•
Rocker arm shaft run-out
Place the rocker arm shaft on two V
blocks and inspect the shaft for bend
using a dial gauge.
If the amount of this run-out is small,
press the shaft with a bench press to
correct the run-out Replace the shaft if
the measured value exceeds the limit.
•
Rocker arm shaft diameter
With an outside micrometer, measure
the rocker arm shaft diameter at the
point where the rocker arms have been
installed.
Replace the rocker arm if the amount of
wear is beyond the specified limit.
- 78 -
Set Length
Spring
Limit
force
Valve Spring
Intake
Tension at 37mm
61.8 ~
61.8 kg
valve
Set Length
68.3 kg
Exhaust
Inner 34 mm
36.1 ~
36.1 kg
valve 39.9 kg
EA0M4056
Spring tester
EDM2037I
Limit 0.2 mm
EA8M3002
Standard Limit
23.978 ~ 23.959 mm 23.75 mm