Originally Posted by SierraNevada
Anyone knows when the timing change needs replacement or
does it need replacement at all.
93 Wrangler 4.0L 124K miles.
when it breaks
seriously, not often at all. timing belts shouldn't go more than 90k or so. your chain will last a long time, i've seen higher mileage that have some play in them, but are far from braking. if you want to be pro active i still wouldn't worry till 150k. i don't think jeeps use nylon gear sprockets, chevy's did, and they nylon gear would wear out.
unless you're having a problem with it, or you have the cover off for some reason, i wouldn't worry yet.