The timing chain does not require replacement unless it has failed.
Chain
The timing chain does not have a recommended change interval and should last for the life of the engine.The timing chain does not have a recommended change interval and should last for the life of the engine.
It has a timing chain.
It has a timing chain.
This vehicle has a timing chain.
Chain.
The 2003 2.5 CRD Jeep Cherokee has a cam belt not a chain
Chain
It has a chain with a cam gear and crank gear.
timing chain
chain
The timing chain (not belt) is not a thing that you should have to replace on a mileage basis. Just keep the engine in tune, change the oil per manufacturers recommendations, and drive it. By the way, a timing belt should be changed approximately every 75K to 80K miles. Your engine will have a chain.