|
| note |
- Mark D.O.R. before removing.
- Check for wear.
- Do not kink.
-
- From model year 2004, a new toothed belt tensioner is installed. To tension and
release toothed belt, use special tool Pin wrench (MB995207). The tensioner has an additional
hexagon hole as shown in the illustration. This does not alter the procedure.
- Adjustment work on toothed belts must be performed only on cold engines, as the
indicator on the tensioning element changes depending on the engine temperature.
|
1.Remove upper guard for toothed belt.
2.Remove belt pulley vibration damper.
3.Remove lower and centre guards for toothed belt.
4.Turn crankshaft to TDC No. 1 cylinder.
|
|
5.
| note |
Turn crankshaft until marking on crankshaft pulley and tooth segments of camshaft sprockets
are on top. Marking on toothed belt guard must align with camshaft sender wheel as shown in
the illustration.
|
Lock crankshaft toothed belt pulley with special tool Crankshaft stopper (MB995209).
6.To do this, push crankshaft stop into teeth of toothed belt pulley from its face side.
| note |
- The marks on the crankshaft toothed belt pulley and the crankshaft stop must align.
- At the same time, the pin of the crankshaft stop must engage in the drilling in
the sealing flange.
- The engine bracket must be loosened only when the assembly mounting has been removed.
|
7.Mark direction of rotation of toothed belt.
|
|
8.Loosen camshaft sprocket securing bolts "1" and "2" until camshaft sprockets can be turned
in elongated holes.
9.Lock hubs using special tool Sprocket locking pin (MB995206). To do this, slide locking
pins through outer free elongated holes into holes in cylinder head.
10.Loosen tensioning roller securing nut.
|
|
11.Turn special tool Pin wrench (MB995207) anti-clockwise until toothed belt tensioning roller
can be locked with special tool Locking pin (MB995208).
|
|
12.Turn special tool Pin wrench (MB995207) clockwise to stop and tighten securing nut "1"
hand tight.
13.Remove engine bracket downwards.
14.Remove toothed belt first from coolant pump and then from remaining pulleys.
|
|
Remove securing bolts for coolant pump and carefully remove coolant pump.
| note |
Always renew seals and gaskets.
|
|
|
Remove crankshaft toothed belt pulley. To do this, lock toothed belt pulley using special
tool Crankshaft sprocket stopper (MB995201).
| note |
When bolting on counter-hold, place two washers between toothed belt pulley and counter-hold.
|
|
|
1.Using special tool Sprocket holder (MB995214), loosen hub securing bolt "1."
2.Loosen hub securing bolt about 2 turns.
|
|
3.Fit special tool Sprocket puller (MB995215) and align it with holes in hub.
4.Tighten securing bolts "1."
5.Apply tension to hub by evenly tightening puller "2" until hub separates from taper
of camshaft.
| note |
When doing this, hold puller with 30 mm spanner.
|
6.Remove hub from taper of camshaft.
|
|
2.Using special tool Sprocket puller (MB995214), tighten securing bolts "1" for hubs to
the specified torque of 100 N·m.
|
|
3.Push camshaft sprockets onto hubs.
| note |
The toothed segment of the camshaft sprocket must be on top as shown in the illustration.
|
4.Hand tighten securing bolts "1" and "2" on camshaft sprockets so that there is no
play.
|
|
5.Lock hubs using special tool Sprocket locking pin (MB995206).
|
|
1.Moisten new O-ring with coolant.
2.Insert coolant pump in cylinder block and tighten securing bolts to the specified
torque of 15 N·m.
| note |
The coolant pump plug faces downwards.
|
|
|
|
1.Tensioning roller must be locked with special tool Tensioner locking pin (MB995208)
and secured to right stop.
|
|
|
2.Camshafts are locked using special tool Sprocket locking pin (MB995206).
|
|
|
3.Crankshaft is locked using special tool Crankshaft stopper (MB995209).
|
|
|
4.Rotated camshaft sprockets in their elongated holes clockwise to stop.
|
|
|
5.Fit toothed belt to crankshaft pulley, tensioning roller and camshaft sprocket and
idler roller.
|
|
|
6.Then fit toothed belt on coolant pump toothed belt pulley.
|
|
|
7.Install engine bracket from below and insert lower securing bolt.
|
|
|
8.Loosen tensioning roller securing nut and pull out special tool Tensioner rocking
pin (MB995208).
|
|
9.
| note |
Ensure that tensioning roller seats correctly in rear toothed belt guard as shown in the
illustration.
|
Now carefully turn tensioning roller clockwise using special tool Pin wrench (MB995207)
until indicator is in middle of gap in base plate as shown in the illustration.
10.Ensure that securing nut does not turn as well.
11.Hold tensioning roller in this position and tighten tensioning roller securing nut
as follows: 20 N·m and 45° (1/8 turn) further.
| note |
When securing nut is tightened, indicator will turn maximum 5 mm to right out of base
plate notch. This setting must not be corrected because the toothed belt will settle after it
has run a while.
|
|
|
12.Apply special tools FR hub & end yoke holder (MB990767) and Pin B (MB991802)
as shown in the illustration. Press them in direction of arrow keeping camshaft sprocket under tension.
13.In this position, tighten camshaft sprocket securing bolts to the specified torque
of 25 N·m as shown in the illustration.
14.Remove special tools Sprocket locking pin (MB995206) and Crankshaft stopper (MB995209).
15.Turn crankshaft two rotations in engine D.O.R. and set again to TDC No. 1 cylinder.
|
|
16.Lock hub "A" by turning in engine DOR until special tool Sprocket locking pin (MB995206)
engages while turning.
17.Check whether:
- Hub "B" can be locked using special tool Sprocket locking pin (MB995206).
- Crankshaft can be locked using special tool Crankshaft stopper (MB995209).
- Tensioning roller indicator is centred or maximum 5 mm to right of base plate notch.
18.If the hub "B" cannot be locked:
Loosen camshaft sprocket "A" securing bolts "1."
| note |
Hub "A" must be locked using special tool Sprocket locking pin (MB995206).
|
|
|
19.Turn crankshaft until hub of camshaft sprocket "B" can be locked using special tool Sprocket
locking pin (MB995206). Loosen camshaft sprocket "B" securing bolts "2."
|
|
20.Turn crankshaft slightly against engine direction of rotation until the pin of the crankshaft
stop is positioned just before the hole in the sealing flange as shown in the illustration.
21.Now turn crankshaft in engine direction of rotation until crankshaft stop pin engages
in sealing flange whilst turning.
|
|
22.Apply special tools FR hub & yoke holder (MB990767) and Pin B (MB991802) as shown
in the illustration. Press them in direction of arrow keeping camshaft sprocket under tension.
23.In this position, tighten camshaft sprocket securing bolts as shown in the illustration.
24.Remove special tools Sprocket locking pin (MB995206) and Crankshaft stopper (MB995209).
25.Turn crankshaft two rotations in engine D.O.R. and set again to TDC No. 1 cylinder.
26.Repeat check.
27.Tighten both upper bolts of engine bracket to the specified torque of 45 N·m.
28.Tighten lower bolts of engine bracket to the specified torque of 45 N·m.
29.Install centre and lower toothed belt guard.
30.Install belt pulley vibration damper, and tighten them as follows: 10 N·m + 90° (1/4
turn) further.
| note |
Before installing assembly mounting, tighten all engine bracket bolts to prescribed torque.
|
|
|
|
Install belt pulley vibration damper to crankshaft toothed belt pulley.
|
)
)
)
)
)
)
)
)
)
)
)
)
)
)
)