I have a ranger as said in title. No a/c. I noticed my belt was cracked very badly so I bought a new one. Dayco made for Ford and Mazda 3.0L V6. Looked the same length as the old one so I put it on and all was good. Then about 2 days later it started squeaking very loudly, not all the time, just 1500 rpm and higher. The hotter the motor got (not overheating just to running temp) the higher rpm it took for it to squeak. I put a stethoscope on all the pulleys/pumps and alt. It sounded the strongest on the idler. So I replaced the idler and bearing (which the bearing was bad, but not the source of sound) it wasn't that. So I thought I'd give the belt a couple days, maybe it was too tight causing a bearing to get too tight and squeak. And the more I drove it the louder it got with less rpm needed to make it squeak. So I tried belt dressing, and still no fix. So today I put the old belt back on to see if that was the issue. Sure enough, it started up and squeaked just the same, but I tried the belt dressing on the old belt and it went silent, even at 3000 rpm. So I assume from this the new belt was a smidge too big. Right? Does anybody have a better belt I could try, store said they'd replace it. I'd love a part # if you have one.

 

Did you replace the complete idler or just the bearing and pulley?
I had a weak spring on my idler and it was causing the belt to squeak at high rpm's


Tom in SC

 

Had the same problem with my 1999 ranger 4.0 subcab 4x4.Dayco belt was new but still squealed where started in morning. The belt was a new dayco belt as well .I watch the belt while truck was idling. The belt tensioner would bounce. I replaced belt tensioner with dorman part. I also replaced belt with a goodyear gator back belt.
gator back belts are hard to find but are dam good belts. Don't know why the parts don't ever offer them. Got both tensioner and belt from rock auto quick and cheap.
Tensioner was 21.00 parts stores want 40.00 for same thing. belt and tensioner for like 53.00 including shipping. Kept the old (new) dayco belt as a spare. I think the spring in the old tensioner was weak. No more squealing.

 

I didn't replace the tensioner, I replaced the stationary idler that's opposite of the alternator. It's bolted into a solid bracket.

 

My old belt doesn't squeak now that it's back on. So it's just the new Dayco belt that's too big. The tensioner doesn't bounce when idling or even revving it up a bit, it never even twitches.

 

Drew, Watch the belt tensioner (not idler) . On my 99 with 4.0 sohv the arm of the belt tensioner would bounce. Suspect weak spring in tensioner.
The also replaced belt with goodyear gator back belt. Theese belts don't squeak ever if pulleys are not aligned just right. The belts the parts stores sell today have a harder compound in them assume the last longer. Gatorbacks have cross groves in the belt and made of better rubber.
Have had really good luck with them. I do suspect your main problem the be the tensioner .Hope this helps.

 

cool glad its fixed

 

CONTINENTAL/GOODYEAR Part # 4060872 Gatorback; Poly-V; 6 Ribs / Effective Length 87.25" / Outside Length 88"
Accessory Drive; Poly-V; Without AC
rockauto.com

 

Thanks, I'll look into the gator back