EXAMPLE DATA: not for workshop use
Printed from Motrix. Every value, tool number and instruction is fictional. Volkswagen Golf VII · 1.2 TSI · 77 kW · engine CJZAExample
Toothed belt: removal and installation
- Applies to
- CJZA / CJZB2012-08 – 2015-08Applies to CJZA
- Source
- Authority class A · OEM
- Revision
- Rev. 03 · 2019-04
- Est. time
- 4 h
- Type
- Removal & installation
- Steps
- 14
Fictional procedure: every value, tool number and instruction is example data. Never use it on a real vehicle.
Removing and installing the toothed belt together with the tensioner and idler pulleys and the coolant pump drive belt, engine in the vehicle. The intake camshaft adjuster and the exhaust camshaft pulley are not keyed: the valve timing is set with the camshaft locking tool and the crankshaft locking pin, the friction-locked crankshaft pulley is clamped by a securing bolt while the vibration damper is off, the camshaft adjuster and pulley bolts get their angle stage only after the timing check, the timing is checked again once the damper bolt is tightened, and every single-use bolt is replaced.
Safety notices 3
DANGERRotating belt drive
If the engine is cranked while your hands are at the belt drive, the pulleys can crush or sever fingers. Disconnect the battery earth strap and keep the key/remote outside the vehicle before you start.
WARNINGEngine on the support bridge
With the engine mount removed, the engine hangs on the support bridge only. Do not work under the engine, and do not remove the bridge before the engine mount is refitted and tightened.
CAUTIONRisk of engine damage
Never crank the engine with the starter during this job, never turn the crankshaft or the camshafts while the toothed belt is off, never force the crankshaft against a locking tool, and never use a locking tool as a counterhold: valves can contact the pistons. Turn the engine by hand only, slowly, in its direction of rotation.
Removing and installing the toothed belt together with the tensioner and idler pulleys and the coolant pump drive belt, engine in the vehicle. The intake camshaft adjuster and the exhaust camshaft pulley are not keyed: the valve timing is set with the camshaft locking tool and the crankshaft locking pin, the friction-locked crankshaft pulley is clamped by a securing bolt while the vibration damper is off, the camshaft adjuster and pulley bolts get their angle stage only after the timing check, the timing is checked again once the damper bolt is tightened, and every single-use bolt is replaced.
Fictional procedure: every value, tool number and instruction is example data. Never use it on a real vehicle.
At a glance
ExampleTools 10
Special tools
- MX-T901Camshaft locking tool Locks both camshafts at TDC cylinder 1. Positions only, never a counterhold
- MX-T902Crankshaft locking pin Screws into the cylinder block and locks the crankshaft at TDC cylinder 1. Never a counterhold
- MX-T903Counterhold, camshaft pulley
- MX-T904Engine support bridge
- MX-T909Tensioner adjusting wrench Two-pin wrench for the tensioner eccentric
- MX-T910Counterhold, vibration damper
- MX-T911Securing bolt with spacer, crankshaft pulley Clamps the friction-locked toothed-belt pulley while the vibration damper is off, tightened to its torque row; turn the crankshaft only at this bolt, only in the direction of engine rotation
Workshop equipment
- Torque wrench 5–60 Nm
- Torque wrench 40–200 Nm
- Angle gauge
Parts 10
109Toothed belt & tensioner
- Z9E 408 853 RQuantity ×1Toothed belt, position 1 in Toothed belt & tensioner
- Z9E 408 421 NQuantity ×1Tensioner pulley, position 2 in Toothed belt & tensioner
- Disputed part number: Z9E 408 422 H or Z9E 408 422 NQuantity ×1Idler pulley, position 4 in Toothed belt & tensionerSources disagree: Authority class A · OEMExample OEM EPC: Z9E 408 422 HvsAuthority class B · LicensedExample TechData: Z9E 408 422 N
- N Z73 296 03Quantity ×1Bolt, tensioner pulley, position 3 in Toothed belt & tensionerNew part, single use
- N Z73 443 04Quantity ×2Bolt, camshaft pulley, position 9 in Toothed belt & tensionerNew part, single use
- N Z93 986 05Quantity ×1Bolt, vibration damper, position 11 in Toothed belt & tensionerNew part, single use
121Coolant pump & thermostat housing
- Z9E 482 547 TQuantity ×1Coolant pump drive belt, position 6 in Coolant pump & thermostat housing
- N Z93 426 05Quantity ×1Bolt, coolant pump drive pulley, position 9 in Coolant pump & thermostat housingNew part, single use
199Engine mounting & support
- N Z97 936 06Quantity ×3Bolt, engine support, position 3 in Engine mounting & supportNew part, single use
- N Z97 937 06Quantity ×5Bolt, engine mount, position 4 in Engine mounting & supportNew part, single use
Torque references 10
- Bolt, vibration damper
- Securing bolt MX-T911 (special tool)
- Bolt, idler pulley
- Bolt, tensioner pulley
- Bolt, camshaft pulley · 2×
- Bolt, camshaft pulley · 2×
- Bolt, coolant pump drive pulley
- Bolt, toothed belt guard · 5×
- Bolt, engine support · 3×
- Bolt, engine mount · 5×
Fluids 0
FluidsNone
No fluids needed for this job.
Source 1
- Section 15.3
Document revision Rev. 03 · 2019-04
Related
Before you start 0 of 5 checked
- Engine cold (below 40 °C).
- Battery earth strap disconnected.
- Engine cover and air filter housing removed; coolant expansion tank moved aside with hoses connected.
- Poly-V belt removed.
- Engine supported with the engine support bridge.
Procedure 14 steps
Step 1 of 14 (current): Remove the engine support and the upper belt guard
With the engine held by the support bridge tool MX-T904, remove the engine mount and the engine support on the toothed belt side. The engine mount bolts and the support bolts are single-use: discard them.
Remove the upper toothed belt guard .
Source: Example WSM · Engine · 15.3.1; Example WSM · Engine · 10.1.4
Step 2 of 14: Set the engine to TDC cylinder 1
Turn the crankshaft at the vibration damper bolt in the direction of engine rotation until cylinder 1 is just before top dead centre.
- Check that the slots in the camshaft ends sit above the centre line (Fig. 1). If not, turn the crankshaft one more full turn, to just before TDC again.
- Remove the screw plug from the TDC bore in the cylinder block.
- Screw in the crankshaft locking pin tool MX-T902 to its stop, then turn the crankshaft gently on, in the direction of rotation, until it rests against the pin. Do not force it against the pin.
- Fit the camshaft locking tool MX-T901 and tighten its bolts hand-tight. The locking tools only position the crankshaft and the camshafts: never counterhold against them.
Source: Example WSM · Engine · 15.3.2
Step 3 of 14: Remove the vibration damper
Counterhold the vibration damper with tool MX-T910 and loosen the bolt . The bolt is single-use: discard it.
Remove the vibration damper and the lower toothed belt guard . The crankshaft toothed-belt pulley behind them is friction-locked, not keyed: keep its contact faces clean and free of oil.
Note for installation: the new bolt is tightened to .
Source: Example WSM · Engine · 15.3.3
Step 4 of 14: Secure the crankshaft toothed-belt pulley
CAUTIONPulley can slip
Until the vibration damper is refitted, turn the crankshaft only at the securing bolt, and only in the direction of engine rotation. Nothing else clamps the pulley: turning the other way can loosen the bolt, the pulley slips on the crankshaft and the valve timing is lost.
Fit the spacer and screw in the securing bolt tool MX-T911 in place of the damper bolt. Tighten it to : it clamps the crankshaft toothed-belt pulley so that it cannot slip on the crankshaft.
Source: Example WSM · Engine · 15.3.3
Step 5 of 14: Release the tensioner and remove the toothed belt
Step 6 of 14: Loosen the camshaft adjuster and pulley bolts
Counterhold the intake camshaft adjuster and the exhaust camshaft pulley with tool MX-T903 and loosen their bolts by one turn. Both must turn freely on the camshafts without tilting.
The camshaft locking tool stays fitted: it holds the camshafts at TDC while the adjuster and the pulley are free.
Source: Example WSM · Engine · 15.3.5
Step 7 of 14: Replace the tensioner and idler pulleys
Remove the tensioner pulley and the idler pulley .
- Fit the new idler pulley and tighten its bolt to .
- Fit the new tensioner pulley so that its lug engages in the recess of the cylinder head. Screw in a NEW bolt hand-tight.
Part number disputed: Idler pulley (pos. 4)Authority class A · OEMExample OEM EPC lists Z9E 408 422 H and Authority class B · LicensedExample TechData lists Z9E 408 422 N. Compare the new part with the one you remove before fitting it: Motrix does not choose a winner.
Source: Example WSM · Engine · 15.3.6
Step 8 of 14: Fit the toothed belt
Fit the new toothed belt in this order: crankshaft pulley, idler pulley, exhaust camshaft pulley, intake camshaft adjuster, tensioner pulley (Fig. 2). Keep the belt taut on the pulling side, and do not kink or twist it.
The camshaft locking tool and the crankshaft locking pin stay fitted until the check in step 11.
Source: Example WSM · Engine · 15.3.7
Step 9 of 14: Tension the toothed belt
Turn the eccentric clockwise with tool MX-T909 until the pointer is centred in the setting window (Fig. 3).
Hold the eccentric in this position and tighten the tensioner bolt to .
Source: Example WSM · Engine · 15.3.8
Step 10 of 14: Tighten the camshaft adjuster and pulley bolts: stage 1
Replace the camshaft adjuster and pulley bolts one at a time: take out the old bolt and screw in a NEW one until it just contacts, so that the adjuster or pulley still turns freely.
Counterhold the adjuster and the pulley with tool MX-T903 and tighten the NEW bolts to stage 1 only, the same on CJZA and CJZB: .
Do not turn them further yet: the angle stage follows after the valve timing check, in step 12.
Source: Example WSM · Engine · 15.3.9
Step 11 of 14: Check the valve timing
CAUTION
If you feel resistance while turning, stop at once: the valve timing is wrong and a valve is touching a piston. Forcing on bends the valve.
- Remove the camshaft locking tool and the crankshaft locking pin.
- Turn the crankshaft at the securing bolt tool MX-T911 two full turns in the direction of engine rotation, to just before TDC cylinder 1.
- Screw in the crankshaft locking pin and turn the crankshaft gently against it. The camshaft locking tool must now fit without force, and the tensioner pointer must still be within the setting window (Fig. 3).
- If not: re-establish TDC with both locking tools as in step 2 (turning at the securing bolt, the damper is off), loosen the camshaft adjuster and pulley bolts as in step 6 so that the camshaft locking tool fits, and repeat from step 9 with NEW camshaft adjuster and pulley bolts.
Source: Example WSM · Engine · 15.3.10
Step 12 of 14: Tighten the camshaft adjuster and pulley bolts: stage 2
CAUTION
Turn the bolts through the angle only after the valve timing check has passed, with the camshaft locking tool and the crankshaft locking pin refitted: otherwise the camshafts turn with the bolts and the valve timing shifts.
Counterhold the adjuster and the pulley with tool MX-T903 and turn the bolts a further (CJZA , CJZB ) with the angle gauge.
Source: Example WSM · Engine · 15.3.9
Step 13 of 14: Replace the coolant pump drive belt
At the gearbox end of the cylinder head, remove the guard of the coolant pump drive belt.
The belt runs on fixed centres, without a tensioner. Counterhold the drive pulley on the exhaust camshaft with tool MX-T903 and remove its bolt (single-use: discard it). Take off the drive pulley together with the old belt.
Fit the new coolant pump drive belt on the drive pulley and the coolant pump pulley, fit the drive pulley on the exhaust camshaft with a NEW bolt and, counterholding it, tighten the bolt to . Refit the guard.
Source: Example WSM · Engine · 19.3.2
Step 14 of 14: Complete the assembly
- Fit the lower toothed belt guard .
- Remove the securing bolt tool MX-T911 and its spacer, and at once fit the vibration damper with a NEW bolt , hand-tight. The camshaft locking tool and the crankshaft locking pin stay fitted.
- Counterhold the vibration damper with tool MX-T910 and tighten the bolt to : the torque stage with the 40–200 Nm torque wrench, the angle with the angle gauge. Never counterhold with the locking tools.
- Remove the camshaft locking tool MX-T901 and the crankshaft locking pin tool MX-T902.
- Final check: turn the crankshaft at the damper bolt two full turns in the direction of engine rotation, to just before TDC cylinder 1, screw in the crankshaft locking pin tool MX-T902 and repeat the check of step 11: the camshaft locking tool fits without force, the tensioner pointer is in the setting window. Then remove both tools and refit the screw plug. If a tool does not fit, the valve timing has shifted: do not start the engine, and repeat from step 3.
- Fit the upper toothed belt guard and tighten its bolts to .
- Fit the engine support with NEW bolts , tightened in the sequence (Fig. 4) to .
- Fit the engine mount with NEW bolts and tighten them to . Only then remove the engine support bridge tool MX-T904.
- Refit the poly-V belt.
- Refit the coolant expansion tank, the air filter housing and the engine cover.
- Reconnect the battery earth strap.
- Start the engine: the belt drive runs without noise. Read the fault memory; clear P0016 and P0011 only after a road test shows no fault.
Source: Example WSM · Engine · 15.3.11; Example WSM · Engine · 10.1.4
End of procedure · Rev. 03 · 2019-04 · fictional example data
Sources 3
- Authority class A · OEMExample OEM Workshop Manual: Engine mechanical (fictional)MX-WSM-5G-EA211 · Rev. 03 · 2019-04 · example.
motrix. invalidMarked verified - Authority class B · LicensedExample Licensed Technical Data (fictional)MX-TDS-2026.2 · Release 2026.2 · 2026-06 · example.
motrix. invalidMarked verified - Authority class A · OEMExample OEM Parts Catalogue (fictional)MX-EPC-5G · Data release 20.11 · 2020-11 · example.
motrix. invalidMarked verified
Every source above is a fictional example record. Values in this procedure are example data.