investinwaffles

EDIT:
I got the belt to be silent at idle by keeping it pretty loose, but when the AC compressor, PS pump, or alternator are stressed -- the belt will squeal like crazy until the "load" is removed. Hoping a new belt will solve this, but if this one squeals SO DAMN LOUD when its tight, would a new belt fix that??


Uugh, I am such a noob.

Just got done with the Durango alternator swap because my old alt wouldnt charge at over ~13.5v. Everything went very smooth through that (minus swapping the ****ing pulley out, which took forever). Other than that, I had no squeal at all (even when cold and wet).

So I bolt everything back up, double check all my torque specs, and go ahead and start the XJ up. It sounded perfect for 30 secs (and was charging at 14.3v on my multimeter), until it started squealing like crazy! I immediately shut it off but forgot to check the voltage after it started squealing though.

After I started it back up after checking belt tension, it was still squealing like CRAZY but it was no longer charging! Multimeter read basically the same as when the engine was off (12.3v). It sounds like it is coming either from the main crank pulley, or the tensioner pulley but I cant really tell. The alternator pulley looks almost perfectly in-line with the rest of the pulleys as well.


SO, I have set the belt tensions 5 ways. Loose (-2, -1), what I think is perfect (0), and tight (+1, +2). With the belt at -1. The squeal is alot quieter and more intermediate, but the car isnt charging! -2, the squeal is louder and I can definitely tell that all pulleys are spinning slower than they should be.
+1 is ok, but LOUD, and +2 sounds like I am murdering hundreds of pigs.


FML - I was hoping this repair would be more straight forward but every time I fix one problem, 2 more spring up.

I have changed belts and set tension on other vehicles, but just never a Jeep. I have been loosening the idler/tensioner pulley, then setting the tension using the screw thing, and then re-tightening the idler/tensioner pulley. Is that correct?
I have also tried tightening the idler pulley bolt, then the screw thingy on the top side, then re-tightening the pulley with no success.


Would appreciate a quick sanity check if anyone has some advice or has been through this before
EDIT:
And the alternator isnt really charging any more. Not sure if this is linked to the belt slipping or just another isolated FML situation.

01SiennaXJ

Is the belt in the proper configuration?
If so, my guess is that you need to just keep tightening the belt tension with the idler pulley. The engine will probably bog down if it's too tight..

MtnHermit

Not a clue what this is, but I'll bet the alternator is locked, won't turn, and the squeal is the belt slipping. Easy enough to check, loosen/remove the belt and turn the pulley by hand.

Turbo X_J

Not familiar with the +1, -2 etc. but serpentine belt tension should be about 180-200 lbs for a new belt, 140-160 for an old one using this

investinwaffles

Some updates + answers, but it still is squealing like crazy. I am going to throw my old alternator back in, and pickup one of the belt indicator tools tomorrow.

The squeal is 100% coming from the tensioner pulley. Alternator spins freely, but will not charge unless the belt is tight. When I run the belt tight, it squeals louder and louder as I get to what I thought the old tension was (I stupidly didnt really check how tight the belt was). My mustang likes a tighter belt.

-2, -1, 0, +1, +2 is just a relative indicator. 0 is where I would ideally run it if it didnt squeal so damn loud!

All pulleys are lined up as well. The alternator is out of a 99 Durango, and bolted up perfectly with my modified brackets + a little grinding on the engine block. The alternator was literally just rebuilt (new bearings, brushes, and rewound), and was run for 30mins on a test bench before I brought it home. It of course spins freely and isnt seized (I thought it might be when I first started it up as well).


Damn shame, was supposed to be an easy day and give me time to relax before working. Hopefully I can get it running before work, I hate taking the bus.

investinwaffles

Ok, so heres a new update after working on it for like 3 more hours.

I got the belt to be silent at idle and when revving it in my driveway, but when I put any sort of large load on the alternator (headlights + blower + power windows), it starts squealing really loud again until I turn off whatever I just turned on.

Before I start turning on high-amp stuff the batt voltage is rock solid at 14.3.
When it squeals, the voltage drops to around 13, sometimes back down to 12.3 which makes me think the alternator could be bad, or the belt is slipping (though that is obvious by the sound).

Any ideas?? I feel like I am chasing my tail but I'll keep messing with it tomorrow. The only reason why I find it hard to believe that the alternator is what is wrong is because it was literally rebuilt days ago, and was given a break-in test to make sure it was working.

Firestorm500

Since you swapped pulleys, the # of grooves is going to be correct.

Buy a new, quality serpentine belt and install it.

Try a Goodyear Gatorback belt. I've had to return numerous Gates belts on my '92 because they are hard to keep from squalling. I won't put another Gates on it if this one starts squalling or chirping. The more I tighten them, the noisier they get.

My idler and crankshaft pulleys have been replaced.

investinwaffles

So I swapped the stock alt. back in but the belt is still squealing like crazy. Uugh, I never had a single chirp until I messed with the belt

I was hoping that it was just something else being weird but I guess I'll try one of those gatorback belts. I have a standard autozone $15 belt on it, but at the same time I dont want to drop ~$40 and not solve the problem.

Thanks for the suggestion though! I will try that.

Turbo X_J

Let's go at this a different way; why the "Durango" alternator swap was your original defective? The charging voltage is determined by the voltage regulator within the PCM, the only reason to worry about it is if it's not charging at all. Random numbers such as "only 13.5 V" are meaningless if there is no load on the system, amps are what you should be concerned with ie. more or equal in than out. When the vehicle is running essentially anything above battery voltage (12v) is fine. The squeal, that's the easy part, the belt is loose or worn.

RTorrez1

Before you put on the new belt give it a good washing with some water and dish soap. Sometimes that thin film on the belt will cause the to slip and make them squeal like a stuck pig and no amount of tightening will help. You may even want to try washing the old belt to see if it help. Just scrub it with a nylon brush and make sure you get all of the soap off. Keep us updated.

investinwaffles

New alternator is swapped in (Because I would constantly get a battery warning light + batt voltage would drop), and it sounds great at idle and when driving it - but starts squealing super loud when I turn the blower on full, headlights and turn signals on, and mess with the power windows. It does not stop until I turn off something major (blower or headlights), and then it instantly sounds perfect. The voltage drops considerably then as well (down to 12.6 or so at idle and 13.2ish at 1500rpm). If I rev it more, it sounds exponentially louder and i dont want to glaze the belt.

I think you may be right, but this one is less than 10K miles old.. I want a gatorback belt, but I cant find anyone that carries it in Denver (and shipping is like 5 days or so). Lame, but I'll do it if I have to (limp on the old jeep). I am afraid of shredding my belt so I'll probably pick up a $20 Duralast value one in case the worst happens.

I was looking at getting a Dayco or Napa (gates) belt, but they also have terrible reviews. All 3 autozones near me definitely didn't have any Gatorbacks that would fit though.



If I tighten the belt down more, it starts squealing like crazy all the time.
Its hard to pinpoint, but I am 80% sure its coming from the idler pulley, but it could also be the main crank pulley as well. Alternator sounds perfect but stops charging when the squealing starts. No wobbles though, and everything looks lined up.

12.6v is what my battery reads at rest, which is why I am thinking that the car has stopped charging? Its a brand new 850CCA battery so it has tons of juice, but it still scares me. Only happens with a full electrical load/AC, and stops instantly when I disengage it, so I know the belt is slipping - but going tighter sounds worse, as does looser.

EDIT:
I am actually home for the day, and I'll give the belt a good scrub-down right now to see if it helps at all. Thanks for the suggestion!

RTorrez1

Yeah, Give it a try. I got to the point when ever I need to install a new serp. belt I always wash them down so I won't have a problem with the squealing. BTW, What ever you do DO NOT spray the belt with any belt dressing. That stuff isn't made for serp. belt and will only cause more problems by making it squeal even more plus it will cause the belt to fail prematurely. If washing the belt helps at least it will give you time so you can order your new Gatorback bet. Hope it works. Good luck!

xjsnake

Tighten that sum***** down really freaking tight and see what happens.

Firestorm500

See my post #7. Overtightening didn't help.

I wonder if MOPAR still makes a belt for these?

NewKindOfClown

No.

Overtightening DOESN'T help. It wears out the pulleys. Gatorback is the way to go, like you said.