Operation Manual

Job Card No.:
Engine:
Filing No.:
Valve Clearance Checking
0178-11-10 1065
© 0185
01.01.01
S/BVM 628
Checking
Check inlet and exhaust valve clearance and adjust
as necessary. Inspect upper valve drive.
Excessive clearance causes the valves to
open jerkily, so the cams may be damaged;
insufficient clearance results in failure of the
valves to close completely, so they will be
destroyed by the gases streaming out.
Job:
Open indicator valves of all cylinders. Unscrew bolts
(1) and remove rocker chamber cover (2). Turn
crankshaft so the respective piston is in compressi-
on TDC and the tappet roller will rest on the cam
base circle.
Clearance "X" between valve stem (6) and socket (5)
should be 0,2 mm (inlet) and 0,5 mm (exhaust) re-
spectively with engine cold.
If clearance is not correct, release locknut (3), insert
feeler gauge beween stem (6) and socket (5) and turn
pressure screw (4) until gauge can only be moved
with a slight drag.
Retain screw (4) in this position and retighten locknut
(3). Recheck clearance. Before refitting cover (2),
check that gasket (7) is intact, otherwise renew.
Close indicator valves.
For ease in determining compression TDC
(both valves closed), proceed as follows:
Remove inspection cover from injection pump ansd
observe respective pump element spring: as the
spring starts being compressed while crankshaft is
slowly turned, the exact TDC position is obtained.
Tools:
- Standard tools,
- Feeler gauge
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