Loud squealing issue!

My jeep from day 1 always had this "squeal" when I turn the a/c on, if the a/c is off and crank up the Jeep it would be as quiet as a can be when idling...

my jeep was in the garage the past half year with several issues, its back up and running now, again quiet when i start it up sitting there idling, but if say the a/c is on, it squeals so so loudly and it does NOT go away. It used to go away after a few minutes of driving...

What are all the possibilities of this issue? I am assuming, its the pulley. Is there a certain number the bolt is supposed to be tightened to? and speaking of this, what's the # the tensioner pulley supposed to be tightened to?

Thanks for any help!

Jessica

What year is your Jeep?

Sounds like the belt needs to be tightened. There's not much of a spec without using a gauge. I just tighten it until you can't easily twist it.

Just tighten or replace the belt.

The belt is new, I have an early model 96 (still OBD I) XJ 4.0L 4WD Automatic.

Do I tighten it until it's absurdly tight or how tight?

with the engine off, grasp the front of the AC clutch (not the pulley) and give it a spin. If it spins freely its good to go.

the spec is pretty darn tight, Ill usually run the engine, and keep cranking on the adjuster until it no longer squeals, then turn off the engine and snug down the locking bolt

Getting it too tight can damage/excessively heat/wear the water pump, idler or other component bearings. I've had to replace the water pump after over tightening a belt before. Makes me feel like a fool, as I know better than that. My main issue is way low temperatures causing belt squeal, which isn't likely your issue.

May be your A/C bearings are starting to seize.

Newer belts tend to stretch some and require occasional readjusting.

Best way is to get a belt tightening gauge and tighten it to spec.. they really aren't expensive, though finding a good one can be difficult.

My quick check method is to stand in front of the motor, find a spot about half way down the belt on the right side of the A/C drive pulley and push with two fingers (hard) 1/2"-3/4" play is likely OK, just a little on the loose side. I tend to err on the loose side.

Coolant soaked belts may squeal not matter what you do, they get sticky and tend to chirp and squeal. Oil covered belts may slip easily and squeal.

Spray on belt dressings seldom help and are actually likely to make it worse.

Soak the adjuster with a good penetrating oil, the threads tend to seize.

souske said:

with the engine off, grasp the front of the AC clutch (not the pulley) and give it a spin. If it spins freely its good to go.

the spec is pretty darn tight, Ill usually run the engine, and keep cranking on the adjuster until it no longer squeals, then turn off the engine and snug down the locking bolt

Click to expand...

If you use this method be darned careful where you stick your fingers and/or shirt sleeve. Just thinking about doing it this way makes my sphincter tighten.

I've been real nervous around rotating parts since I saw a guy lose a handful of long hair and scalp

How about buying a belt tension gauge and not have any questions as to how tight the belt is?
It's the only true way to set the FSM spec accurately and prevents damaging over-tightening.
http://www.summitracing.com/parts/gtr-09002?seid=srese1&gclid=CJ-jjZ3T9L4CFSwS7Aod0SsA2w
New belt 180-200 ft/lb
Used (more than 15 minutes run time) 140-160 ft/lb

I should have specified, I.use.a 30" extension to tighten the.adjuster. not getting my booger hooks anywhere near that.fan.while its spinning.

One other thing to consider, the shop could have installed a cheap belt (they typically squeal). I have good luck with Goodyear gatorback belts. Or use a Napa (built by gates) belt. Or use a dealership Mopar belt.

IH392 said:

One other thing to consider, the shop could have installed a cheap belt (they typically squeal). I have good luck with Goodyear gatorback belts. Or use a Napa (built by gates) belt. Or use a dealership Mopar belt.

Click to expand...

I've had good luck with GY Gatorback belts as well.