Terrible Squeal in engine compartment

[keithert]

My Tracker has been making a terrible squealing sound when the weather has been cold or wet. It has been getting steadily worse. I have been thinking the problem is a bearing going bad in the alternator. Today I loosened the alternator belt and the sound went away. If I tightened it the sound came right back. The odd thing is that both the alternator and water pump pulleys turn just fine when the belt is disconnected. Would either the alternator or water pump spin more easily when the belt is disconnected but show bearing issues when the belt is tightened? I put the alternator in a vise and turned the pulley with my impact wrench to get it spinning fast. When doing this it didn't show any binding at all.

[Paladian]

it is your belt. i have the same problem with mine. replaced the belt and about 2-3 months later it started again. so i bought a can of spray that stops the belt from sliping and squealing i did think of tightning the belt but was a bit worried if it went tighter that bearings in water pump and alternator would die. does anyone have any good way of knowing how tight to have belt?

[HotTommy]

According to the FSM for my 89 Tracker, proper belt tension is set when thumb pressure (about 22 pounds) applied to the belt midway between the fan and the crank pulley deflects the belt 5 to 8 mm (0.2 to 0.32 inches). It also noted that there are other possible sources of noise from the generator.

[mozukkc]

Yes it is the belt. My 94 has had the same problem since I owned it. I did find a stripped bolt on the bottom of the alternator bracket and tightened it and it helped but not as much as I would have liked. I use the belt spray stuff every month or so and it is minimized also if I let off the gas for a second and give it gas again it goes away. I wonder if a undersize pulley would help?

[keithert]

I replaced the alternator and the belt. No more squeal.