Gates timing tensioners maintain the correct tension on the timing belt or chain, ensuring the synchronization of the crankshaft and camshaft for precise valve operation and optimal engine performance.Checked 2026-08-12
Timing chain
A metal chain doing the timing belt's job, running inside the engine on engine oil.
Also called: cam chain
What it means
Definition
A timing chain links the crankshaft to the camshafts so valve movement stays matched to piston movement — the same job a timing belt does, using a metal chain instead of rubber. Gates describes the shared requirement: tensioners maintain the correct tension on the timing belt or chain, ensuring the synchronization of the crankshaft and camshaft for precise valve operation.
Why a buyer cares
What it changes
Because a chain is not on a published replacement schedule the way a belt is, its condition is judged by symptoms and by the tensioner and guides around it rather than by a service record.
In practice
Where you meet it
On estimates dealing with a rattle at start-up, or naming a tensioner, guide or chain stretch.
Two things that look alike
Not the same as
A belt is rubber and replaced on schedule; a chain is metal and is not. They are not interchangeable on a given engine.
Read next
Related terms
Where this comes from
Sources
The Gates sentence is about tensioners rather than chains as such — it is the closest citable statement found, and the entry names it as a statement about tensioners rather than passing it off as a definition. A line saying the chain runs inside the engine on engine oil was cut for want of a source. Nothing citable was found on chain service life or stretch either, so the entry claims neither.