I did a pretty deep creek crossing last weekend on a trail ride and got a progressively worsening whine that varies with engine RPM. I was sure it was my power steering pump, because it sounds like a bad PS pump, so I flushed the system and then replaced the pump yesterday. No change at all.

I did the old breaker bar stethoscope trick on both the PS pump and the AC compressor, and the whine definitely sounds like it's coming from the AC compressor. It still blows cold, and the sound doesn't change when the AC clutch is engaged or disengaged.

Anyone run into this before? Clutch bearing? Did I somehow frag my compressor but it's still working? I have like zero free time to work on this thing in the near future but it's killing me to have it parked at the back of the driveway.

Could be the clutch bearing going bad.

If you have the tool (puller) it’s not that bad of a job.


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Like a standard 3 jaw puller, or a Toyota SST? And do the refrigerant lines need to be disconnected to do it?

Is it possibly the idler pulley?

You are absolutely correct on that.


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Could be, although it’s a relatively new part. I’m still thinking it’s something in the AC compressor based on the way it sounds through a breaker bar.

Idler pulley is a cheap and easy part to try though, so maybe I’ll give that a go too.

It requires a puller tool. Which threads into the center of the clutch with a bolt in its center that presses of the clutch.

I have a kit for Sanden compressors used on American models. I used it twice so far.


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You don't need a puller to remove the clutch from the compressor body. Once you remove the bolt holding the hub on (a 1/4" impact wrench works well) you can remove the hub. Be careful to not lose the shim(s) that space the hub to set the air gap. They look like small washers. Once the hub is off, you can access the snap-ring that holds the pulley on. the bearing is pressed into the pulley and often staked in place. If it's staked, you'll need to grind those off and then press out the bearing and press the new one in. This can be done without needing to discharge the system as long as you can position the compressor to allow access to the front without needing to remove it from the car. The bearing number is Santech MT2027.

did you try replacing the tensioner pully? mine was loud forever and finally did it. took 20 minutes and cost 20 bucks. noise gone

Cool, thanks for that part number!

I haven’t yet, but when I get some time to work on it I’m going to pull the AC belt just to isolate that system to be SURE that’s actually where the problem is. I’ll check the idler while I’m in there and see if there’s any play.

it's worth the cheap price of the part to replace. I pulled mine off and spun the bearing. I thought nahh... it seems fine. but it was the cause. doesn't take much on these bearings as they are spinning pretty fast and have tension on them. just my 2

Being that you notice this after off reading ,I would expect the idler pully on the ac as it's the lowest pully bearing on our rigs. May not be. Just a thought.

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Still haven't had time to work on it, but found this thread while looking for Japanese-made bearings, figured I'd link it here for reference: Toyota Denso AC Compressor bearing and Idler bearing replacement

Got an NSK bearing and Toyota idler pulley on the way.