Never. This is not an item you replace at a scheduled time or mileage. It should last the life of the engine.
A loose timing chain should be replaced.
It has a chain
Timing chain usually needs to be replaced each 180-200K miles.
Should be a belt not chain
unless there is noise coming from the timing chain, you should never need to replace it.
at what milage should the timing chain be replaced on a 95 ford aerostar
never needs to be replaced
This truck has a timing chain, not a belt. The chain will last longer than a belt and should not be replaced until it fails.
It has a timing chain which will last the life of the engine.
nissan micra has timing chain or cam chain and should be replaced at 200.000k
It doesn't have a timing belt. It has a timing chain and it will last the life of the engine.
You are correct that the SL2 uses a timing chain. However, since it uses a timing chain it does not need to be replaced as does the timing BELT. In general, a timing chain should last the life of the engine.