Idler pulley? Nope just put on a new one.
Fan clutch? Nope, started it with the fan off, still squealing (I'm installing a new one anyhow)

Since I have both fans and shrouds removed, I could locate the sound better. Seems to come from the passenger side of the engine. Doesn't change if A/C is engaged or not, so I'm pretty much ruling that out. The alternator pulley spins really smooth, no resistance or rough spots that I can feel, so I think that's good. Whatever it is the fan pulley attaches to has more resistance than I think it should. What is it called, and where do I get one?

I figure I'll go ahead and replace the water pump while I have easy access, too.

Just for fun facts: 1996 Cherokee Sport 2WD, 4.0, AT. 120k miles. I'm the third owner. Bought it from my grandfather who bought it in 1999 with 99000 miles on it. He kept it covered in his garage, averaging 2k miles per year of ownership. It's in GREAT shape!

So the question is: What is this thing called?

 

mine squeeled bad. i changed my powersteering pump pully and that fixed it.

 

Don't know the techinal name of it fan blade mount maybe it will be a dealer item or bone yard part.

 

try some belt dressing and/or new belt.
mine squeeks bad also, but only sometimes and only if i have the a/c on... i just sprayed some wd-40 into my a/c bearings and its gone.

 

I hadn't given that much thought to the PS pump, because the sound seems to originate from the other side... I might give it another listen.

 

That would be an easy fix, but no, the belt is less than three weeks old.

 

belt might just need to be adjusted a little bit.

 

mine does it, iys usually the bearing inside somethin that make that sound

 

Mine was doing the same thing and a belt adjustment fixed it. It is CRAZY how tight the belt needs to be and if your belt is new it may have stretched a bit already.

 

IMO belt dressing will DESTROY a serpentine belt faster than anything! Have you tried the harmonic balancer? It may need tightening...

 

Check your belt tension.X2 on that belt dressing its bad for belts.

 

I don't think that's it, mainly because it doesn't change at all under load. I had replaced the belt about three weeks ago because it would squeal when the A/C compressor kicked in, or even occasionally just with the headlights on.
I'm pretty sure it's a bearing, I just have to find the right one. And I do HAVE to find it, because its driving me crazy!

 

Another thing you can try is get a stethoscope or even just a long screw driver. Put it up to each accessory as its idling, close to the pulley and listen. You can usually narrow it dow this way if is a bad bearing on an accessory. Becarefull not to get it caught by the belt though.

 

Ding ding ding! I think we have a winner!

As I was testing/listening one last time, the belt jumped off. Strange, thought I, I know I routed it correctly. Reinstall belt, crank her up, belt jumps before I even get out the drivers seat. Look closely, idler pulley not lined up. Remove/verify correct idler pulley installation. Still not lining up - with the harmonic balancer. Looks like it has scooted forward. I'll snap a picture before I fix it.

But first, how do I fix it? I had a friend of mine replace a balancer on a Tempo one time, but I didn't participate so don't know what's involved. I see RockAuto.com has a balancer and a balancer sleeve kit. Do I replace the whole thing? Just tighten the big bolt in front? Buy the sleeve kit?

Again, I've never done this and would appreciate some advice!



Pretty flippin obvious NOW where the problem is... You can see it doesn't even come close to lining up with the other two pulleys in this picture.

 

Problem solved with new harmonic balancer. I wound up with a new balancer, idler pulley, fan clutch, water pump, belt, and thermostat.
I should be good to go for a while!

Thanks to all who offered advice