I have a 2001 V70 with 139K. A/C starting to blow cool, not cold, cool air then periods of warm air and back to some cool. Does not cool the cabin of the car down. Pep Boys ran a diagnostic and informed me would need a new a/c compressor and dryer to the tune of $1800 and change. I ran the price on Discount A/C parts and can get them for $450 shipped. However, Pep Boys to install with freon, etc, and other charges, total with parts that I buy and they install will be around $1100. I've read briefly about shimming the a/c clutch. Cost and worth while?

On sources for parts - anyone try Erie Vo-Vo on ebay motors? They are selling the a/c compressor for $149. Thanks

 

I will bet you can reshim the compressor and it will work fine.
Here is how to do it.https://volvoforums.com/forum/volvo-850-16/c-compressor-clutch-reshimming-6665/
If you remove you cooling fan then you can unscrew the compressor and pull it back and turn it up. Then you can take it apart and reshim it.