73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: hoser on May 08, 2010, 12:54:29 pm
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Hi all long time no see glad to see the site is still here...
The bearing on my sons truck a/c compressor was starting to get loose and grumble so we decided to change it, his compressor works great the a/c is ice cold, he has had the truck 4 years and their is no freon leaks, the clutch works perfectly so we decided to change the bearing, I did one of these 20+ years ago and it was no big deal.
So I went to a friend of mines auto business and borrowed his a/c puller kit, not wanting to risk doing damage to his compressor we have another old used R4 compressor to experiment on so we rehearsed everything, we pulled apart the old compressor on the bench it went normal everything came apart.
Now we had practice we took my sons clutch apart while still installed on the truck, first thing we noticed is the nut that holds the clutch plate on was missing, maybe this is a rebuilt compressor and they forgot? We went ahead and took the clutch assembly off and apart everything went perfect no problems, with new bearing in hand we went back to my buddys shop to press out the old bearing press in the new, the bearing change went normal only pressing on outer race of the bearing (been installing bearings for 35 years) as you should so no stress is on the balls.
We started installing the new bearing on the compressor and got it about 1/2 way on and I notice the bearing is now locked up or so hard you can barley turn the pulley on the compressor, at this point I figure I have nothing to loose and keep driving it on with a driver on the center race, get it all the way on its easier to turn but its clearly not right.
So back to the OLD mock up compressor we have on the bench lets try that one, the bearing turns freely by hand uninstalled, same thing soon as you start to install it get it on about 1/2" its hard to turn, drive it all the way on and seat it so you can install the snap ring and its still almost locked up.
I dont get it, both new and old do the same, the old bearing spun freely before we took it apart now it spins hard when reinstalled, the bearing race is about 1" wide so it has to be setting on the shaft square, if this only happen to the new bearing and not the old I would think maybe one of the bearing races we the wrong diameter and it was deforming when installed, I have to be missing something here some place but cant figure it out, figured I would walk away and go ask, and go do some reading.
Never bothered to ask any of my mechanic buddys their answer is to replace everything with new and give them 1000 bux thank you see you next time you have a problem type guys, the dont rebuild anything just parts changers.
If you need any pics let me know.
GM manual does not show anything special to replace the bearing.
Thanks in advance.
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Ok figured it out, the face of the clutch is flexible if you look at it, when pulling the clutch off you pull from the outside of the clutch and it bends the face then when you reinstall the clearance between the inside of the clutch and the compressor housing rubs the only way I can see you can line it up again would be to tap it with a hammer to bend it back so the pully runs true, cant believe none of this is covered in the factory service manual.
To avoid all this they should have had provisions to pull from the center hub so it does not distort the clutch face.
Dumb design.
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I have about an inch of dust on my ac compressor tools. I just get reman'd compressors now because it's just not worth it