the big timing belt question

[jeep-N-montero]

So the guy I bought my 98 from said he never had the timing belt changed and he wasn't sure if his brother who owned it before him had it done either. But I was checking the belt when I was doing the valve cover gaskets and it is free of any cracks and passes the "fingernail test", when you dig your fingernail into it the rubber indents like it should when new. I'm going to rotate the crankshaft to see if I can read a brand or part number on the belt, should be easy to determine if it's the original belt or not.

If I decide to change it in the next few weeks, which special tools do I need and does Autozone rent them out?

 

[jeep-N-montero]

Almost forgot the big question, have any of you actually ever had the belt break while driving?

 

[1morebike]

i did but mines a 90 so i got away with it

 

[jlocster]

I'd replace it if in doubt, there's too much to lose if it breaks. Remember, you have an interference engine. While you're in there change the water pump, cam seals, front main seal, and make sure you have the updated harmonic balancer bolt (MITSUBISHI 1100A141 Crankshaft Bolt, 3rd Version), the previous versions are prone to failure.

Special tools and pics here

 

[limp_noodle]

How'd the water pump look? If that looks old then I would replace the belt. Also, how's the tension on the belt?

 

[dlh62c]

Almost forgot the big question, have any of you actually ever had the belt break while driving?

The belts can stretch and the tension pulley can only take up so much slack. The belt then jumps the pulley teeth resulting in a shredded mess. Some engine designs result in the valves contacting the pistons when the belt breaks, which isn't good.

 

[Mudrunner]

Yes update that bolt, I had the old one and now I have had to replace the Crankshaft timing gear and now a hydro tensioner all because of that bolt.