Timing Chain replacement on 2001 Jeep G. Cherokee

If it is the timing chain, they cost about 30 bucks and 4 to 6 hrs of labor so your quote is way out of line. If you do not change oil often regularly, the timing chain can suffer. 100K with a loose chain is not unreasonable though some usually get a lot more than that. Engines with manuals tend to have the timing chain last longer than with a automatic as a auto put more strain on a chain with constant sudden RPM changes from shifting gears where with a stick they tend to be smoother about this. If you are comfortable with tools and do not mind getting a tool or two if you need it it is quite doable. I would also recommand that you replace water pump while you have it off given its mileage as it may be reaching the end of its life cycle and since you have to remove it to change the change, replace the pump while it is off.