Do you grease the timing chain on a jeep wrangler 4.0 when replace it?

No, you do not grease a timing chain on a Jeep Wrangler 4.0L engine (or any other engine for that matter) when replacing it. Timing chains are designed to run in an oil bath. Adding grease would be detrimental, potentially attracting dirt and causing the chain to slip or fail prematurely. The engine oil provides the necessary lubrication.