Timing Chain Tensioner: Service and Repair

PRECEDING WORK
Poly V-belt removed.
Air cleaner with mass air flow sensor, right, removed.
Intake air scoop, right, removed.
Secondary air pump removed.

OVERVIEW





Crankshaft:
Turn to 30° after TDC on 1st cylinder.
Plug (1):
Loosen approximately one turn.
Chain tensioner:
Unscrew completely, remove.
If the chain tensioner housing (14) has been loosened, it must be removed, because the thrust bolt (10):
Has engaged in the locking spring (9) in the thrust direction.
Filler pin (7) and pressure spring (8):
Unscrew, remove (step 4).
Thrust bolt (10):
Press out of chain tensioner housing (14) in thrust direction together with catch spring (9) (step 5).
Chain tensioner housing (14):
Install with sealing ring (15), tighten to 50Nm (step 6).
Thrust bolt (10):
Slide in together with catch spring (9), pressure spring (8) and filler pin (7) (step 7).
Plug (1):
Install with sealing ring (5), tighten to 40 Nm (step 8).
Leakage:
Check.

NOTES





Improved noise characteristics in engine speed range 900 - 1200 rpm when engine is at normal operating temperature as a result of modified chain tensioner.
Pressure pin (10) 1.1 mm diameter control bore (identified by 3 grooves on 14.2 diameter). Compression pin (8) wire gauge 0.7 mm (was 0.6 mm).
Standard as of August 1991.
Engine 120.980-12-003 128
120.981-12-000 068

REMOVAL, INSTALLATION





1 Turn crankshaft to 30° after ignition TDC on 1st cylinder (arrow).
2 Loosen plug (1) approximately 1 turn.
3 Completely unscrew chain tensioner and remove.
4 Remove plug (1) with sealing ring (5). Remove thrust spring (8) together with filler pin (7).
5 Press out thrust bolt (10) together with catch spring (9) in thrust direction. Clean parts.





6 Screw in chain tensioner housing (14) with new sealing ring (15) and tighten to 50 Nm.

Installation note
Stick seal (15) with grease to the chain tensioner housing (14) so that it remains centered on the guide shoulder.
Tightening torque 80 Nm.





7 Insert thrust bolt (10) into installed chain tensioner housing together with installed catch spring (9) and pressure spring (8) with filler pin (7).





8 Screw plug (1) into installed chain tensioner housing (14) with now sealing ring (5) and tighten to 40 Nm.
9 Allow engine to run and check for leakage.

TIGHTENING TORQUES IN NM






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