DSG-423 ENGINE
02-18
Valve Tappet - Replacement
CAUTION: During engine repair procedures,
cleanliness is extremely important. Any foreign
material, including any material created while
cleaning gasket surfaces, that enters the oil
passages, coolant passages or the oil pan can
cause engine failure.
NOTE: Valve tappets are select fit and the valve
clearance must be checked before removing the
tappets -- Refer to“Valve Clearance Check” on page 45
of this section.
1. Remove camshafts -- Refer to“Camshafts -
Removal” on page 18 of this section.
CAUTION: If the camshafts and valve tappets are to
be reused, mark the location of the valve tappets to
make sure they are assembled in their original
positions.
NOTE: The number on the valve tappets only reflects
the digits that follow the decimal. For example, a tappet
with the number 0.650 has the thickness of 3.650 mm.
2. Remove and inspect valve tappets.
3. Reverse procedure to install.
NOTE: Coat valve tappets with clean engine oil prior to
installation.
Camshafts - Removal
CAUTION: The crankshaft, the crankshaft sprocket
and the pulley are fitted together by friction, with
diamond washers between the flange faces on each
part. For that reason, the crankshaft sprocket is
also unfastened if you loosen the pulley. Therefore,
the engine must be retimed each time the damper is
removed. Otherwise severe damage can occur.
1. Remove and/or disconnect components to allow
access and removal of the timing drive components.
Label if necessary to allow for correct reinstallation.
2. Remove timing chain and sprockets -- Refer
to“Timing Drive Components - Removal” on page 14
of this section.
CAUTION: Failure to follow the camshaft loosening
procedure can result in damage to the camshafts.
NOTE: Note the position of the lobes on the No. 1
cylinder before removing the camshafts for assembly
reference.
3. Loosen the camshaft bearing cap bolts, in sequence
shown, one turn at a time.
4. Repeat until all tension is released from the
camshaft bearing caps.
5. Remove bearing caps and camshafts.
Camshafts - Installation
CAUTION: Install the camshafts with the alignment
slots in the camshafts lined up so the camshaft
alignment plate can be installed without rotating the
camshafts. Make sure the lobes on the No. 1
cylinder are in the same position as noted in the
removal procedure. Rotating the camshafts when
the timing chain is removed, or installing the
camshafts 180 degrees out of position, can cause
severe damage to the valves and pistons.
NOTE: Lubricate the camshaft journals and bearing
caps with clean engine oil prior to installation.
1. Install the camshafts and bearing caps. Tighten bolts
in the sequence shown in 3 stages:
• Stage 1: Tighten one turn at a time until tight
• Stage 2: Tighten bolts to 7 Nm (62 lb-in)
• Stage 3: Tighten bolts to 16 Nm (12 lb-ft).
Valve
Tappet
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