When to replace timing belt

[Rossg59]

I just bought my first Chevy, a 2003 S10 LS Pickup with a manual tranny, 4 cylindar engine and 85K miles. The truck is exceptionally clean, and the engine compartment immaculate. She drives like new. My question is when should the timing belt be changed? Unfortunately, I don't have any maintenance records for the truck and the owner's manual doesn't even mention a timing belt.

Thanks.

[goongrinch]

s10s have a timing chain

[Rossg59]

Thanks for the correction. And when does one replace said chain?

[goongrinch]

there isnt a sceduled time to replace them most say just wait untill it breaks or whenever the engine dies.

[Rossg59]

I take it that unlike the old days, if the chain breaks it doesn't destroy the engine? I was always under the impression that the chain should be changed at regular intervals, albiet, not very often but certainly before it actually breaks.

Thanks for the info.

[silicon212]

Timing chains will stretch over time, which will cause problems with valve timing, but they seldom ever break.