A/C Clutch Bearing Replacement

[Peter G.]

I have done several searches here for this topic and came up zero....

My 1973 LS4 with C60....the air conditioning compressor clutch bearing is making noise and I want to replace the bearing.

Has anyone on here done this service before and can you tell me the procedure if possible. I have to big Fridgeaire compressor that is born with my car.

Thanks in advance for any help and advise.

[Terry M.]

Re: A/C Clutch Bearing Replacement

I assume by big Frigidaire you mean the A6 compressor. Years ago when I was in school we used to change these routinely, now this is old school stuff. Your copy of the FSM (Factory Service Manual) or Factory Overhaul Manual should have the instructions complete with the pictures we love so much. The tools required will be listed as Kent Moore tools with J-xxxx numbers. You don't need tools from KM. There are other sources on the Interweb for those tools. I wouldn't be surprised if there are videos on Utube that show how to do it. Search for "front bearing on A6 compressor" or "Clutch bearing on A6 compressor."

The major question is whether you need to remove the compressor from the car to make the bearing change or not. Obviously the difference is whether you will need the equipment to recover your refrigerant or not. I can tell you the task is much easier with the compressor off the car. As to whether there is enough room to do this with the compressor on your Corvette you will have to wait on someone who has done it to tell you.

[Chuck B.]

Re: A/C Clutch Bearing Replacement

Peter,
Do you hear the noise with the AC engaged, or only when it is turned off? If you just need to change out the clutch, you can purchase a new AC one from Rock Auto for about $50, and I have the tools you need to remove and replace the clutch.
Chuck Banks

[Harry S.]

Re: A/C Clutch Bearing Replacement

I have done several searches here for this topic and came up zero....

My 1973 LS4 with C60....the air conditioning compressor clutch bearing is making noise and I want to replace the bearing.

Has anyone on here done this service before and can you tell me the procedure if possible. I have to big Fridgeaire compressor that is born with my car.

Thanks in advance for any help and advise.

Peter, the compressor is 43 years old. After that much time there could be other problem. You certainly can replace the parts you believe are bad at a reduced cost. Consider restoring the entire compressor, probably $350.00. On my 63 compressor I had some rust on the inside, a leaking valve and some wear. If you want to have it restores let me know and I will pass the persons name. He is an NCRS member from the west coast.

[Peter G.]

Re: A/C Clutch Bearing Replacement

The noise is deafing when AC is turned on. Now starting to hear very little noise with AC off. belt still on all the time. I know it is the A/C bearing as I did the process of elimation with the fan belts. Thought first it was the Air Pump, but it was good.

I may take you up on your offer.

Thanks.

[Peter G.]

Re: A/C Clutch Bearing Replacement

Thanks Harry...I have had the compressor off the car at least two times since I have owned the car which is ten years. If I think I need a total rebuild I may contact you for your information on a good restoration/rebuild shop. A bearing looks pretty simple however I have never done one so starting to do some research. Sometimes these jobs are easier than they look and sometimes much more difficult than you think. Mostly the latter.

[Richard M.]

Re: A/C Clutch Bearing Replacement

Peter,

When the engine is running and the AC is off, the bearing is spinning with the clutch. If you hear no loud noise in this condition, and because the bearing is not under any load, it may be masking the bearing as suspect.

When the AC is activated, then engaging the clutch, it then puts a greater load on the bearing. In this condition, it may be hard to pinpoint if the loud noise is the bearing alone, or if internal to the compressor, or both.

I'd agree with the consensus that it may be time for a complete overhaul. But to show what some of the pieces look like and what you'd have to do, here's a example....

Bearing replacement can be done with the compressor in place. I had this one on the bench for seal replacement.
P1010012.JPG


A puller/installer tool is needed for this task. Puller is lower right in pic below. The installer tool(upper left) is critical to get the proper clutch spacing tolerance on reinstallation.
KDT2416.jpg
The puller is used to remove the clutch/disc(left pic below). This is attached to the shaft of the compressor which drives the internals. It only spins when the AC is activated. Once removed, the magnetically driven housing(pictured on right) can be pulled from the compressor snout. The inner race of the bearing is a press fit over the snout, so a puller is needed to remove the assembly from the compressor body.

The outer bearing surface is pressed into the drive housing itself. Once it's removed, the bearing can be replaced using a hydraulic press.

P1010013.JPG

Once the bearing is replaced the clutch disc is installed using the install "puller". A feeler gauge is used to set the clutch to the drive disc. THis spec is important for proper engagement.

Here's a step by step to give a idea. Although it's a Jag, it also uses the A6.

http://www.bernardembden.com/xjS/comclutch/index.htm

===

[Peter G.]

Re: A/C Clutch Bearing Replacement

Many thanks to everyone for the options and procedures for this. It gives me more to think about. The system is original and still requires R-12 refrigerant which as you know if very difficult to find and when you do it is very expensive. I use to charged auto ac systems at my gas stations back in the 70s. The refrigerant was $7.95 per can and it took two and half cans and the labor was $12.95! My have things changed. So because of this I may change the bearing first and see how it does.

Again thanks.

[Domenic T.]

Re: A/C Clutch Bearing Replacement

Peter,
Richards reply is very good. I just have to say a few cautions. After removing the 9/16 nut inside the hub, that will be the only time you can press against the shaft with a puller. The other is when you use the shaft to pull the clutch hub back on the shaft. When you remove the pulley from the housing you must use the special tool so you do not press against the shaft or you will damage the thrust bearings or move the swash plate position on the shaft. That tool is in Richards reply. Placing the pulley back on the front flange also needs a special tool if the compressor is on the car. If on the car, the tool is used to lightly tap the pulley on the flange so you can put the snap ring on, off the car the tool is used to press the pulley on. The tool used to tap the pulley on the front flange is to make sure you don't hit the shaft. The hub must NEVER be tapped on with a hammer to put it in place or it WILL damage the thrust bearings or move the swash plate position. The most important thing is to use the correct tool to PULL the clutch hub back on the shaft. The clearance between the hub to pulley is in the book, but must never be closer than .022 or I believe .058 away. The distance can vary around the hub clutch, but must not vary less than .022 or greater than .058. The 9/16 nut should have a shoulder smaller than the head of the nut. The nut is put on shoulder first to clear the snap ring inside the clutch hub. That snap ring did not have to be removed. After putting the 9/16 nut back on, check the space between the clutch hub and pulley to make sure it did not move closer than .022. In a perfect World when you tighten the 9/16 nut it should not move that distance closer than .022.

Dom

[Gary J.]

Re: A/C Clutch Bearing Replacement

Peter, I just sent my compressor to Domenic for rebuilt and what a beautiful job he did. I can't speak about the performance yet as the car is having a frame off restoration, but I feel sure it will perform better than factory. The only down side was shipping to California and back. By the way he even put a new decal on it date coded it.

[Harry S.]

Re: A/C Clutch Bearing Replacement

Peter, I just sent my compressor to Domenic for rebuilt and what a beautiful job he did. I can't speak about the performance yet as the car is having a frame off restoration, but I feel sure it will perform better than factory. The only down side was shipping to California and back. By the way he even put a new decal on it date coded it.

Gary, Dom did a compressors for me and two other members of the New England Chapter. All three came back as works of art. Performance, mine is blowing better than 20 degrees ambient and that is better than factory specs.