Timing Chain

[BobCSmith]

I'm going to be replacing the Radiator (upgrading to a 3-core) and AC Conderser (has a leak) on our 91' Cherokee 4.0 with 170,000 miles on it.
I hear a slight rattle from the front that some has said it sounded like a timing chain. Since I'm pulling the radiator anyway, would this seem like a good time to replace the timing chain?
I've never replaced one myself, how involved is it and roughly how long does it take on an average?
Thanks

 

[DaveD in Canada]

Although its probably not critical at that mileage, its not a bad idea to change it if you have the opportunity. Its a Saturday job for a novice mechanic. You will need a puller for the crankshaft damper, and new seals and gaskets. The gears are keyed and marked, so you can't really mess it up. Its pretty straightforward, being you already have the rad out.