Cummins ISF2.8 Timing Chain Replacement

Replacing the timing chain Cummins ISF2.8 (GAZelle NEXT)

We replace the chain when it is stretched and remove it during engine repair.

To replace the chain, the engine must be removed from the GAZelle NEXT vehicle.

Tools and materials required

To carry out the work you will need: 5 and 6 mm hex keys, 10 and 15 mm sockets, and a tool to hold the phase sensor trigger wheel and prevent it turning. You will also need a torque wrench, a mallet or rubber hammer, and wire to secure the chain.

Materials and parts used:

New timing drive chain. It is recommended to use an original part or a quality equivalent. The chain is replaced when it stretches, which shows up as running noise, valve timing shift and faults on the camshaft position sensors.
New timing case cover gasket.
New chain tensioner cover gasket (if necessary).
Heat-resistant sealant for the mating surface of the flywheel housing to the cylinder block.
New tensioner shoe and chain damper — in case of severe wear.
Engine oil (for lubricating the parts during assembly).
Rags, cleaner for removing remnants of the old sealant and contamination.

Important: the flywheel housing weighs about 23 kg, so it must be removed with an assistant. The flywheel housing securing bolts differ in diameter and length — their location must be remembered or marked before unscrewing.

Preparation and removal

We remove the engine.

We set the No. 1 cylinder piston to TDC on the compression stroke (article – Setting No. 1 cylinder to TDC).

We unscrew the five bolts securing the timing case cover.

Five bolts around the timing case cover — The timing case cover is secured by five bolts — unscrew them evenly

We remove the cover.

Exposed timing case cavity — The removed cover exposes the chain and the drive components

We remove the gasket. A new gasket must be fitted on reassembly.

We unscrew the two bolts securing the chain tensioner cover.

Two bolts on the chain tensioner cover — The chain tensioner cover is held by two bolts

We remove the cover.

Chain tensioner cover removed — Beneath the cover is the chain tensioner plunger

We extract the tensioner plunger.

Tensioner plunger withdrawn from its bore — The plunger is withdrawn carefully so as not to damage its surface

We secure the chain by tying it with wire.

Timing chain tied with wire — The wire stops the chain slipping off the crankshaft sprocket

We slacken the bolt securing the trigger wheel and the camshaft sprocket while holding the shaft to prevent it turning.

We fully unscrew the bolt securing the phase sensor trigger wheel and the camshaft sprocket.

Spanner on the camshaft sprocket bolt — The camshaft must be held stationary while the bolt is slackened

Caution: after unscrewing the bolt securing the phase sensor trigger wheel and the camshaft sprocket, neither the crankshaft nor the camshaft may be turned, so as not to disturb the valve timing.

Trigger wheel and sprocket bolt withdrawn — Once the bolt is out, the crankshaft and camshaft must not be turned

We remove the wheel.

Phase sensor trigger wheel removed from the shaft — The trigger wheel is removed together with the camshaft sprocket

We remove the sprocket together with the chain from the camshaft nose.

Camshaft sprocket with the chain fitted — The sprocket is removed together with the chain, without letting it slip off

We extract the spacer washer so as not to lose it.

Thin spacer washer on the shaft nose — It is best to put the washer aside straight away — it is easily lost

We secure the timing chain together with the sprocket on the engine.

Chain and sprocket secured on the engine — The secured chain will prevent the valve timing being disturbed during further dismantling

We unscrew the two bolts securing the timing case to the flywheel housing.

Two bolts in the lower part of the timing case — These two bolts join the timing case to the flywheel housing

Location of the timing case securing bolts.

Diagram with numbered timing case bolts — The diagram shows the location of all the timing case securing bolts

We remove the clutch housing.

Clutch housing removed from the engine — The clutch housing is removed after detaching the timing case

We remove the flywheel (article – Removing and fitting the engine flywheel).

We unscrew the ten bolts securing the flywheel housing to the cylinder block.

Ten bolts securing the flywheel housing to the block — The flywheel housing is secured to the cylinder block by ten bolts

The flywheel housing securing bolts differ in diameter and length; their location must be remembered.

Flywheel housing bolts of different length and diameter — Before unscrewing, it is best to mark the bolts or lay them out in their places

The flywheel housing weighs 23 kg, so it must be removed with an assistant.

Flywheel housing being removed — Because of its considerable weight, the flywheel housing is removed by two people

Using a mallet or rubber hammer, we free the housing and remove it together with the starter motor.

We unscrew the bolts securing the tensioner shoe “A” and the damper “B”.

Bolts securing the tensioner shoe and damper — The tensioner shoe “A” and the damper “B” are secured by separate bolts

We extract the bolts and remove the shoe and damper.

Tensioner shoe and damper removed — The removed shoe and damper are inspected for wear

We inspect the tensioner shoe “A” and the damper “B”; in case of severe wear, we replace them.

Tensioner shoe and damper showing signs of wear — In case of severe wear, the shoe and damper are replaced with new ones

We extract the camshaft sprocket from the chain.

Camshaft sprocket extracted from the chain — The camshaft sprocket is extracted from the chain before the chain is removed from the engine

After taking the chain off the intermediate gear sprocket, we remove it from the engine.

Fitting the new chain and reassembly

We refit the chain and all the parts in the reverse order.

Before fitting the flywheel housing, make sure that the two dowel sleeves are still in place.

Dowel sleeves on the block mating surface — The dowel sleeves must remain in place before the housing is fitted

We apply heat-resistant sealant to the mating surface of the flywheel housing to the cylinder block.

Diagram with the flywheel housing bolt numbers — The flywheel housing bolts are tightened in the order shown in the diagram

We tighten the bolts in the order shown in the figure. The M8 bolts are tightened to 24 N·m, and the M12 bolts to 85 N·m.

We check the valve timing.