Clutch or Bearing Noise? - Getting Bad

[psa55]

Seems about right.. Winter is here and my old TB doesn't seem to like it. I've developed a bad clutch or bearing noise somewhere in my serpentine belt system. I've taken the belt off and checked the pulleys/bearing on the idler, tensioner and alternator and they all seem fine. The water pump was done a couple years ago and replaced with a new AC Delco. It had developed quite a shutter sound and was easy to identify (there is a video on here from a few years ago). So, that leaves me with an AC compressor, Thermal Clutch fan, is that right? The default sounds when cold and on startup is loud... then something engages/disengages when it is at idle, but only briefly before getting loud again. It pretty easy to hear in this short 25 second video:

Anybody with any insight on the sounds in this video and what part I should be looking to replace here? This TB is now my 17 yr olds daily runabout and I'd like to avoid any breakdowns for her. You can hear her in the video in a big hurry to go nowhere important and annoyed with me!

 

[aaserv]

You can stop the clutch fan while its running and see if the noise changes or stops. I wrap a thick towel around my hand and drag it on the right side of the blade to a gradual stop.

 

[TequilaWarrior]

Start the vehicle and turn your HVAC OFF. Does the noise change at all? Set HVAC to MAX COOL and turn the temp all the way down.... does the noise change at all? If there is NO DIFFERENCE between these two scenarios, my first guess would be (unfortunately) the water pump. That sounds exactly like my water pump before I replaced it. They have short lives in this platform. When the bearings in the water pump go, they can be VERY noisy.
However, if the noise changes between HVAC ON and HVAC OFF, it's likely the bearing in the compressor's clutch. That's a whole different kettle of fish. I believe there are threads here discussing changing that bearing. I'm not aware of how difficult it is to replace said bearing without removing the compressor (which in itself is a PITA to do and is fraught with peril).
Another observation to take is with HVAC ON, watch the clutch face on the AC compressor. You should see start and stop as the compressor cycles. You'll likely hear an audible "click" with each start/stop. If your noise follows that start/stop, that's a dead giveaway, too. BUT, if the noise follows the start/stop, it's possible it's not the bearing, but clutch slippage on the AC compressor. In which case, removing the air gap shim may solve your issue (tedious, but free). There are also threads here covering that.

 

[coolasice]

Sounds like the ac compressor clutch to me... mine made similar noises then just started squealing all the time and eventually burnt itself out... You can get a shorter serpentine to bypass the ac clutch entirely if you don't want to deal with it right away... would be a simple way to test also, belt was like $20

D&D PowerDrive 25060695 Napa Automotive Replacement Belt, K, 6 -Band, 70.25" Length, Rubber: Amazon.com: Industrial & Scientific

D&D PowerDrive 25060695 Napa Automotive Replacement Belt, K, 6 -Band, 70.25" Length, Rubber: Amazon.com: Industrial & Scientific

www.amazon.com

 

[Sparky]

The sound in the middle of the video reminds me of when my alternator bearings went out. But the changing sound makes me think compressor. It doesn't sound like the when my compressor pulley bearing went bad, but then, it has been so many years I don't really remember it that well. Technically, you have to replace the whole entire *#%(@# compressor, BUT there is info on what bearing you can buy to replace just the pulley bearing. In my case, I bought the bearing, then found when I removed the pulley that the clutch surface on the pulley was ground down to about nothing somehow and trying to press that bearing out would have cracked it. Blah. I ended up buying a random used compressor I found at a junkyard just to steal the good clutch plate and pulley from (which I put the near bearing in before installing on mine).

My water pump never failed in all its years and 215k miles of life, so I have no idea what sound it makes when it goes bad. Actually, the only water pump I've ever had fail was on my first car (93 Ford Taurus), everything else has been fine. Maybe I'm lucky. I've had problems with just about every other pulley driven part, but not the water pump!

 

[Mooseman]

Technically, you have to replace the whole entire *#%(@# compressor, BUT there is info on what bearing you can buy to replace just the pulley bearing.

I have found a clutch kit but it's from China. It's been good for me since.

A/C Clutch Kit from AliExpress

Continuing from this post, starting this thread to document and review this clutch kit...

gmtnation.com

 

[psa55]

Thank you for the advice here! I've been unable to replicate the noise this week. I've tried switching the HVAC between Max Cool and Off, but no change. I can't see magnet or clutch engage/disengage or hear it, like I normally would. AC seems to be working just fine.

Took the belt off again and started spinning things again.. This 15 sec video seems to identify a bad bearing on the AC Clutch. Local parts place I deal with didn't have a 70" belt, but it should be here tomorrow. I'm gonna keep it with the TB for emergency backup to bypass the AC system (can always return it). @Mooseman TY for the link to the AC clutch kit from AliExpress. Looks like that is the only option for the parts.

 

[psa55]

So, I finally got around to this chore. My daughter runs the TB around daily now, and she is away for the week, so I figured now was the time. I got the part @Mooseman suggested earlier in this thread back in January.

This went quite smoothly. I followed the instructions for water pump removal here to undo the fan and remove the fan assembly. (https://gmtnation.com/forums/threads/how-to-replace-the-water-pump.15639/)

I then followed Mooseman writeup, which was perfect. I used a three-jaw flywheel puller to remove the pulley. Toughest part wasn't the removing the Circ-Clips, but actually getting the larger one back in. I had to modify the length of my snap-ring pliers by trimming the ends a bit, to get the clip back into the proper slot. Everything else went as expected.

The bearing was definitely worn out, and I'm lucky it didn't result in a bigger more pressing issue, earlier. Everything is back together and the AC is blowing cold as ever.

With much appreciation for everyone here,
psa55