Annoying squeak from serp. belt. Just replaced bearings and tensioner 4 months ago !

Hey guys ! Trucks starting to develop a really annoying squeak. The last few weeks it was awful upon startup, sounded like the truck was dieing. After about 15 minutes of driving the squeal would slowly die down and be almost non existant. Today, the squeal did not go away, frost has fallen and im wondering if the moisture content in the air maybe ramp up the intesity of the squeak. It lasted as long as i drove the truck, about 70-80km.

The part I dont understand, is i just spend 800 at the mechanics to get all the new bearings replaced ( besides the AC compresser, if that has one , unsure ) and new pully systems + a new belt. i was told this would correct my problem, but now it seems im back to square one.

Also, I had left the truck sitting for about 2.5 months while i was away at work, could that time with the truck sitting have rusted out the new bearings in the tensioner and pulley system?


Thanks for the help !

 

First, let's be sure it's the belt or not the belt. Some morning, get someone else to start the truck. When it begins making a bucket of noise, take a bar of soap and let the soap rub against both sides of the belt (it acts as a quick, rubber-safe lubricant). If you're worried about losing fingers, a few shots of WD-40 will be OK (not too much). If it quiets down, sounds like it's the belt to me.

Usually a belt will shut up as it gets warmer, which has me thinking it's a bearing. Could be a pulley was overtightened or undertightened, either of which can cause that sort of noise. So the next step would be to hit each pulley bearing, one at a time, with another shot of WD-40 or PB Blaster. Just enough to quiet things down. Eventually you'll find the suspect bearing and can fix it from there.

If you use WD-40 or PB Blaster, use it sparingly. It's an Okie way to do things, but it works.

 

Alright so to update, i tired spraying all of the wheels very lightly with wd40, it made the squeel definitley quiet down a fair amount, but the aqueak was still their. So , after i sparingly hit the wheels i took the wd40 to the actual belt itself, spraying both sides as the truck was running. Now the squeak goes completley away ! But after driving the truck for an hour or 2, or turning it off for a few hours, the squeak comes back immediatley when the truck is started from cold.

Is it my belt ?

 

Do you have a mechanic's stethoscope or even just a long piece of fuel hose you can stick in your ear? If you listen to each accessory and pulley you can usually tell pretty clearly which one in making noise. I actually noticed something in my accessory drive making noise last month and now it's getting more pronounced so I got out the stethoscope and sure enough one of the idlers is noisy. So tonight I'll be installing it.

I've also had experience with some cheap belts just being plain noisy especially when cold. Spraying belt dressing on a serpentine system often has the exact opposite desired effect also.