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Question:

Bad alternator or bad water pump pulley?

My '95 Ford Ranger has had the sound of a bearing going bad in a pulley for about two months. Finally this weekend I started it up and it must have locked up, the belt was squealing really loud and snapped. So, now the water pump pulley has rubber chunks on it, which would make me think that is the bad pulley. But the pulley spins perfectly, really smooth. The alternator pulley on the other hand does not spin perfectly. It is not really hard to spin, but it does not spin smoothly. And the alternator pulley is real clean, no rubber on it at all. Any thoughts? I was thinking of buying a cheap belt and putting it on there, have someone start the truck and watch under the hood to see which is bad.

Answer:

not a good idea, find the bad part first, could be < idler pulley, tension, power steering pulley, air conditioner compressor pulley ( if it has air ) , alternator besides that, there ain't any CHEAP belts that i know of
Bad Alternator Pulley
open your alternator and replace the bearing. there are two bearings, behind the pulley and at the end of the rotor near the slip rings then install new belts. check the rotation of both the water pump and alternator after work before installing belts. you may also check air condition compressor bearing if so equipped. check idler bearing ,if so equipped.. in short, all rotating parts/pulley you see.
Well from your description I would say it's the water pump, as that is where the residue is but if all the pullies are spinning by hand I would suggest gtting a throwaway belt and looking for yourself. Also if you had any overheating problems before than I would lean to the water pump, or if you had any dead batteries or charging problems I would lean to the alternator then. What about the A/C compressor that could also be the problem, so could a tensioner as well. So I stick with my original statement and try to get a cheap belt and look for yourself, just make sure you wear protective glasses so if it does snap you dont lose your eyes actually just be careful when you do it OK!!! Good Luck, Tony
First, you should have checked it when it started, instead of thinking it will go away. Well, it went away. Go ahead and buy the new belt. before you put it on, lubricate the idler pulley bearing. After you put it on, have someone else start the car while you eyeball the water pump pulley and the alternator pulley. Whichever one that appears to be skipping is the bad one.

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