hi everyone, i have a 1990 s10 blazer with a 4.3 l. that today blew a belt i need the proper routing and any ideas on the cause. i noticed an unusual noise for a few day. today, battery light came on briefly, someting seized, belt smoked and broke. all pulleys (alt, a/c power steering and 1 idler spin freeley, 1 idler spins but that that fast. alternater pulley has rubber remains and appears discolored. it may be alternator or and idler. any ideas on how to tell.
thanks for any inputs or similar problems

 

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i would try to move all the pulleys up down, back and forth, in out and you should be able to find something loose. if not then maybe something got caught up in the belt from underneath and jammed it until it broke. try putting a new one on and go from there.

 

ryan, thanks for belt routing. something definately seized and caused belt failure,

 

Try sticking a long screwdriver to the bolt on the pulley you want to inspect or the bracket it bolts to, and the other end to your ear. Then turn the suspect pulley and listen to how the berrings sound. If they sound crunchy then that device is toast. If your battery light came on I would suspect the alternator. It may spin, but what happens when you pull the pulley up and down? If there is any movement you may have smoked the berrings in the alternator. A new alternator is going to be a couple hundred bucks, but a rebuild kit is only about 30 and has all the parts you will need in it (2 berrings, a voltage regulator and the brushes and springs). Its not that hard to rebuild an alternator, the tricky part is putting the 2 halfs together without the brushes falling out. Use paperclips in the holes to hold the brushes back while you put the halfs together, then pull the paperclips out once its together. You should also check from the side of your engine to see the alignment of the pulleys. If the tensioner arm is busted it will stick out like a sore thumb. Putting a laser pointer on a known straight pulley and rotating it so it shines on the others is a good way to see whats inline and whats not. Im sure with the screwdriver trick you will see which one is your demon. Oh also you should have a belt routing sticker on the bottom side of the hood, look up while you are looking at the engine. Another easy way to route the belt is this - grooved pulleys have the grooves run on them, smooth pulleys have the back of the belt ride on them. Good luck man, let us know how you made out.

 

the battery light could have come on because the alternator was not spinning right before the belt broke because something seized up, so the alt was not putting out voltage for a split second and turned that battery light on.


thats a great idea with a laser, i would have never thought of that.

 

You could also look at each pulley to see which one is shiny. If it seized and the belt kept turning over it, it will polish to a shine in no time at all. If belt alignment is a problem, then one side of the broken belt will also be shinier than the other side.

Ive had one of those lasers in my toolbox forever, they are really handy that way. They are also good for checking tires for out of roundness or separated treads.

 

thanks to all that replied. changed belt today and tried long screw driver trick to verify vibration in alternater replaced and all is well thanks