Squeaky belt

[kryptyk]

I have a 2007 Ram 1500 with the 5.7L HEMI and can use some help.

I'm chasing a squeak that's intermittent, but seems to be coming from the belt. I've replaced the belt, idler pulleys, tensioner (the new one bounces like the old one and feels like the same amount of tension being applied), and the power steering pump pulley (it was chipped). The PSP pulley is aligned and everything is torqued. There's no oil on any of the pulleys.

It squeaks quietly while idling (I can only hear it with the hood up and standing in front of the engine).

It squeaks loudly on occasion, but I can't get it to repeat, except when making a specific left turn close to home (no place else does it happen pretty much every time). It's more frequent going up hills. Up until this week, it didn't do it at highway speed. It lessens when I get off the gas (most of the time).

I've seen mention of a couple of possible sources.
The harmonic damper - I marked the damper with a paint pen. We'll see if it slips.
The alternator clutch - with the belt off and holding the fan in place, the pulley doesn't turn on either direction. So far as I can tell, I just have a plain pulley and not an OAD or OWC (Google it's only so helpful). I'm leaning towards this because my lights dim when I slow down and brighten considerably when I speed up. The engine will bog down when I slow down too (it'll sometimes down to 400 RPM before it catches itself probably exacerbating the lights dimming).

Can you guys think of anything else it might be?

Also, does anyone know if I can replace just the alternator pulley to fix a bad alternator clutch (if there even is one)? I'll swap the whole alternator if I have to, but legal flights with ex-wives aren't cheap.

 

[kryptyk]

If anyone is wondering, no, there is not a clutch on the Gen 3 Ram alternator. Also of note, Amazon seems to sell a pulley for it, but there isn't a way to verify it against a part number that I can find.

I've been trying to pay more attention to the squeak recently. I don't think it's exclusive to going straight and turning left, but I haven't heard the squeak when turning right.

Sadly, still no idea what's causing it.

 

[FaceDeAce]

Well.... I just recently went through similar. Had squeaks and squeals under the hood that were bothering me. As you, I replaced the 3 idler pulleys, the tensioner, the belt. That quieted it down a bunch but the problem did not actually fully go away until I replaced the alternator. The belt wasn't slipping. The issue was the bearings in the alternator were getting dry and their roller cages getting noisy. The rotor brushes were also worn to near nothing. So, this truck here is on its 3rd alternator now.
All of those things replaced are wearable parts. Nothing "wrong" or to fix with them. They just wear out and need replacement.

I'd say your next step is to just replace the alternator. I doubt the problem is the pulley; as with mine its internals are probably just at the worn out point.

*** that bog when you slow down. Could be and probably is another wearable part. The EGR valve gets sluggish and sticky as it ages. If it stays partially open when it shouldn't, then you get reduced power, bogging, oscillations or even stalling at stop signs. Replace that too. Not an expensive part and easy to do.

PS: my 5.7 hemi powered ram is now pushing upwards of 330,000 Km. It is still running very well, but not without regular basic maintenance and replacement of those wearables from time to time. I've not "yet" had to go any deeper than replacing spark plugs, pulleys, alternators, and exhaust manifold bolts.

Hope that helps!