About a month ago, a sound started happening every time I started the truck, I associated it with the fan belt, because it was starting to get colder in the mornings. However, this sound occurs every time I start up the truck, the noise is there, and it has gotten worse. It happens every time I start the truck and sounds like a fan belt squeel, only its quite loud and lasts about 10 seconds. The belt is not at all loose, and the sound seems to be coming from the alternator. I sprayed all of the bolts on the pulleys with WD40 and some white lithium grease. That hasn't done anything to quiet the noise.

Does anybody know what this noise could be, and how I could get it to stop? I'm hoping its not an alternator problem or anything worse... would the alternator be covered under the warranty?

 

10 seconds, eh? That's too long to be what I have. My starter makes a squeal as it spins to a stop after it disengages -- no doubt from spending too much time underwater.

Just because the belt isn't loose, doesn't mean it hasn't become glazed from slipping after offroading has wet and dirtied it. How many miles do you have on the truck, John? Would it be worth your while to just change the belt? A gatorback is a good idea for offroaders anyway, and might solve the problem.

Right after you startup, the alternator is a big load as it zaps a charge back into the battery to make up for what you just used starting. It could be that the belt has just gotten "slick" and slips under that load.

 

I have somewhere around 35,000 on the truck with the original fanbelt. You can hear the noise coming from right by the alternator, so thats why I'm unsure its the belt. Do the belts usually start going around 35,000?

 

I've got about 43,000 on mine, and it's just now starting to squeek at startup. Original belt that came on the truck, too. If you change your belt, let me know if that fixes it.

 

Yes, they certainly can, John. Serpentines can go earlier than that in some cases. 3.0 Rangers are TERRIBLE on belts.

Yeah, I think you should get a Goodyear Gatorback and try it. I bet it fixes it.

 

I would start with the belt.

 

Is it hard to change out the belt? Maybe we/I can do that when I come to visit on Sunday John.

 

john you can do it, its easy, get the free loaner serp belt tool from autozone, saves you some time. and do get a new belt. yeesh, 35k miles!! i think i change mine around every 15 or so.

 

maybe its your idler pulley?

i know on emily's old ranger it squealed like heck, we changed it and it sounded fine at first, but then started to squeak again

 

If you need a good place for gatorbacks... I have a wholesale place by me. I think they ship too.

MAke sure you get the right one. Autozone has the wrong number for the 4.0
They list the 3.0 belt number for BOTH!
(3.0 belt is like 3" to long)
Also the orginal belt was superceded by a new part number.

I think the orginal was like 88.8 the new one is 3/10 inch shorter.
so 88.5 (that isnt the right length just an example)

Rand

 

Have any of you tried using soap-stone on the backside of the belt? That usually helps depending on how bad it is!

 

I hate the 3.slow now. I had a belt squeal at around 44k miles and then I put on a Gatorback belt. Well now I'm at 46k miles and it's doing it again. I haven't had time to check to see where the sound is coming from yet, but I'm hoping its the belt and not one of the pulley or worse yet the alternator. And also I don't do any offroading, this has to be from rain.

 

I took the tensioner and idler pulleys off, disassembled the bearings (carefully remove circlip and dust seal), cleaned them with solvent, re-packed them with white lithium grease, reassembled it all and it STILL SQUEAKS when it's humid or rainy out. New belt seems to be the cure (Gatorback). If mine did all the time, I'd get one, but it's gone by the time I hit the first stop sign, so I live with it.