MTU 12V4000C*5 series, Operating Instructions Manual

Page: 172 / 305

Diagram for 20V engines – Two
crankshaft positions
Valve clearance at two crankshaft positions – Check
1. Check TDC position of piston in cylinder A1:
• If rocker arms on cylinder A1 are unloaded, the piston is in firing TDC.
• If rocker arms on cylinder A1 are loaded, the piston is in overlap TDC.
2. Check valve clearance with cold engine:
• Inlet (long rocker arm) = 0.2 mm ±0.05 mm
• Exhaust (short rocker arm) = 0.5 mm ±0.05 mm
3. Check all valve clearances in two crankshaft positions (firing TDC and overlap TDC of cylinder A1) as per
diagram.
1 Cylinder A1 is in firing TDC
2 Cylinder A1 is in overlap TDC
I Inlet valve
X Exhaust valve
4. Use feeler gauge to determine distance between valve bridge and rocker arm.
5. If the deviation from the specified value exceeds 0.1 mm, adjust valve clearance.
Valve clearance – Adjustment
1. Release locknut (1).
2. Insert valve adjusting gauge (3) between
valve bridge and rocker arm.
3. Use Allen key to set adjusting screw (2) so
that the specified valve clearance is provided.
Note: Valve adjusting gauge must just pass through
the gap.
4. Insert valve adjusting gauge (3) between
valve bridge and rocker arm.
170 | Valve Drive | MS15041/03E 2018-08
TIM-ID: 0000062651 - 002