Mercedes-Benz W126 timing chain and valve timing
300 SE300 SEL
When should the W126 timing chain be replaced and how is stretch checked?
The chain should be replaced at about 200,000 km intervals. The stretch is seen by setting the timing marks in line and measuring how far the camshaft mark has moved from its position.
Does a broken timing chain bend the W126 valves?
On the M103 engine (12 valves) yes: when the chain breaks, the pistons hit the valves and the valves bend. That is why the condition of the chain should be checked before it breaks.
Does the new timing chain of the M110 need to be riveted and how long does the replacement take?
Riveting is not needed: the locking clips that come with the new chain are enough for fastening. The replacement takes about an hour. At the same time the wear of the tensioner and the chain should be checked.
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