Timing Chain and Gears

[dduenkel]

I have a 1975 L-48 and while driving the other day the timing chain jumped a tooth. After taking off the timing cover the gears were all torn up also, now these are metal gears and not the nylon ones that I have heard were used so it was replaced at some point. I understand that the chain and stretch a little but what would cause it to chew up the gear? When it jumped a tooth, I was idle at a stop light so it wasn't like the engine was running hard, it jumped and the engine just quit. I can fix the timing chain and gear pretty easily but want to prevent it from happening again. Any ideas?

 

[TimAT]

Was it a morse-type chain or a roller? Upper gear aluminum or steel?
I'd go back with a double row roller and call it a day. Cloyes seems to be a good one, but they're not the only one that makes them.

 

[Vettehead Mikey]

If they're going to jump it's most common at very low speed, during start or shutdown. TimAT suggested Cloyes, I agree.

 

[73shark]

And make sure it's a true double roller. There's two kinds which I wasn't aware of 'til my machinist informed me. Supposed to last a lot longer.