AC Clutch Information (an interesting find)

[RoyalViking]

I recently replaced the serpentine belt and tensioner as the belt had started to fray (I attributed this to mileage). Only the side toward the engine was bad. I also noticed a strand from the belt had been throwing oil around as it made contact with the other parts of the engine, or so I thought. About a week later (40 miles) I noticed that the AC quit working and there was smoke coming from under the hood. I unplugged the AC clutch and thought the coil had begun to fail. So began my search for a new clutch.

The next day I found that the bearing is what usually fails. What I know now is that the belt fraying was due to the heat from the clutch bearing causing the belt to deteriorate. I decided to tear it down to see how bad things were. Getting it apart was no problem. I didn't need the special tools. I did find that a oil filter wrench can work to hold the clutch face while you loosen the bolt.

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This is the pulley clutch face

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This is the coil.

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This is the bearing. The bearing cage was made of plastic and a melted lump of it remains in the bearing. Hence the reason why it looks like some ball bearings are missing.

So what I thought was going to be and easy trip to the parts store ended up to be a long afternoon and about $15 in gas to search for someone who may have it. It turns out that the AC Compressor Clutch for the Denso AC compressor is not a popular item with GM or the part stores. The bearing is no longer available through GM and the part stores do not list it at all. I tried Advance Auto, Autozone, Pep Boys, and another local part store. I did find a replacement on the internet and if it works I'll post the bearing part number and source here. With shipping it cost about $32. The original bearing was made by Toyo and is part number DAC3052-3RDID.

By the way, the new clutch goes for about $150 and I had not even tried to locate one at this point in time. I am wondering if I would have the same trouble in locating the right one. I also found that looking for the bearing online shows bearings for the 10PA20C compressor when in fact the bearing is not correct.

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Denso AC Compressor

 

[tmkassin]

There is a place in Warren Michigan called 'Bearing Service' that has almost any bearing ever made.

 

[MBDiagMan]

Yes, take the bearing to a bearing supply and I'm sure they can provide one.

 

[RoyalViking]

Yes, take the bearing to a bearing supply and I'm sure they can provide one.

I ordered the bearing from bearingsdirect.com The bearing part number is 30BG05S2G-2DS and is described as an A/C Compressor Ball Bearing, dimensions are 30x52x22, for $25.49

I chose going with them as I had already called a company that I had bought bearings from in the past and they were not able to locate a replacement.

Yesterday I had some time to press the bearing in and put the clutch back together. I don't have a press so I used my bench vice. If the assembly is parallel with the jaws the bearing goes in easily. I had to make a few adjustments when I started as it was not parallel. I put a plate against the bearing side to protect it. On the other side I used a large large socket to protect the thin steel ring that is also inserted before the bearing.

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So, it all went together well. I started the car and the AC was working again. It worked for about five minutes and then the compressor locked up. I went into this hoping that the problem wasn't worse that just a bearing failure. I pulled the clutch face off again and found compressor oil on the shaft.

I also found this information at Examining Air Conditioning Clutch Failures in the Field

Bearing Failure
Bearing failures are usually caused by system problems. Very seldom is a bearing itself the culprit of a failed or locked up compressor. For example, if the clutch slips severely due to a high pressure or low voltage condition, or due to compressor slugging, the excessive heat generated by the slipping will quickly melt and destroy the bearing seal. The bearing then loses its grease and locks up or falls apart, usually destroying the clutch in the process.

I've disconnected the coil and at this point I can drive the car again.

I spent $31.75 all together (includes S&H) and go on until I have saved enough to get the AC checked out and working again. :eyerole

Besides I have been looking for agood reason to take the targa top off more often.