A/C Clutch Hub

Folks I've got a squealing sound I first thought was coming from (what I found to be) a cracked serpentine belt. Replaced the belt and the squealing is still present, so.... before I tackle the compressor, figure a clutch hub replacement is a cheap attempt to fix it without the bigger job.

Anyone have the correct part # (aftermarket's fine) and/or can anyone confirm if it's the same part as the 4.0 2nd gens?

 

Use a stethoscope to find out where the noise is coming from

 

maybe an idler. Listen close, and maybe save some dough.

 

Yeah, You should diagnose this and not just throw parts at it.

 

As mentioned by 9th...the tensioner pulley is a common suspect.

 

would the tensioner pulley be a culprit when I can see all of the pulleys spinning freely, and there is zero noise until the A/C engages? Seems I would hear the pulley tensioner without the A/C compressor on, no? In any case I don’t have a stethoscope (on the list) but I did take a broom handle and it does appear to be coming from the center of the clutch area at the compressor.

 

A squealing belt sound is usually caused by a glazed or loose belt, [you replaced] next, could be the tensioner is not keeping the belt tight.
Being that this happens when the a/c is on causing extra load on the belt.. Is it possible to put a wrench on the tensioner and push the tensioner to tighten the belt while it is making noise ? [IF THERE IS ENOUGH ROOM] If the noise stops you know its the tensioner, if not check all the pulleys.

 

All the same stuff is turning except for the innards of the compressor until you turn the AC on including the clutch hub bearing.

 

Thats correct, clutch will spin freely untill its engaged.. TRY THIS, when it starts to squeal, spray a little wd40 on the pulleys. If noise stops you know its a belt slipping. This will only work for a minute or so.

 

That's fair, will do some tinkering this weekend for sure. I suppose could also be a coolant issue potentially. I know that in my truck I've always noticed an abnormal level of RPM spike each time the compressor kicks on at idle. It seems as though the engine strain to kick the compressor on has gotten worse (like truck shakes each time it kicks on) - this could be in my head, but it's always been odd how much strain it seems to put on the engine vs. other vehicles I've owned. I'll tinker with the tensioner and pulleys and see if I can get to the bottom of it. Hoping I'm not in for an expensive compressor replacement which I'd probably pay to have done.

 

I'm sure it's rare, but I'm a bit more sensitive to this given there have been at least a few reports of locked compressors destroying or severely damaging the engine. I would hope it would throw a code and disable the compressor before it came to that, but perhaps not... ?

 

A locked ac compressor will do nothing to a engine other than throw the serp belt. IF it locks and throws the belt you loose power steering and you battery light will turn on right away giving you ample warning to stop and get it towed.

 

Thanks for the feedback folks, what led me to the AC clutch hypothesis was that I watched a couple of vids from 2nd gens who replaced that part to address what sounds like the same sound I have. Will attempt other avenues first though!

 

bahammer0 any updates on your issue? My 2nd gen just started making a squealing sound when the ac clutch engages. My first thought was the clutch was slipping. Thanks in advance!

 

At this point, working theory is oil contamination on the lower idler pulley (to the left of the AC) from the timing cover seep. Dropping it off today to let them get that done and replace the pulley

 

Thanks for the reply! Good Luck!

 

I'll take all the luck I can get. Turned my stomach dropping the truck off this morning. I know most folks have been fine with the fix on the timing cover leak, but still a LOT of things to go wrong when pulling the engine on a 20hr job... It "runs" great - just put 500 miles on over the weekend, but if I stop and idle with the AC it sounds like a dying pig under my hood.

 

Had my truck in the shop for the timing cover leak and had them look into the noise. Tech initially agreed with me that it sounded like a pulley bearing…. But no. Had him puzzled too apparently but eventually he tracked it down…. Exhaust clamp loose. Noise gone. And hopefully my engine will stop leaking now too!