replace timing chain on 1997 Dodge Ram 1500

At what mileage should the timing chain be replaced?

Asked by for the 1997 Dodge Ram 1500
On my '97, 1500, 4x4 I was having a water pump change and repair of an oil leak on the front of the engine. The oil leak was thought to be coming from the crank seal, but was from the timing cover. Long story short, when the cover was removed the timing chain was found to be out of wear tolerance and was replaced. The truck had 106,000 miles on it.
2 more answers
at engine overhaul

Timing Chain is not a Scheduled Maintenance item. They need to be replace only if they are too noisy or something else is wrong with it.