A/C compressor pulley out of alignment

It is the original compressor. My A/C worked fine and then stopped. I discovered that the A/C compressor belt had been destroyed. Picture attached. The compressor was not locked and the clutch and pulley spun freely so I purchased a new belt and installed it. Upon cranking the motor I could hear something wrong so I shut it off and looked at the belt. It had ridden up over the back edge of the pulley. I then removed the stretch belt and put a straight edge on the front of the compressor pulley. It is 1/8” forward of the crank pulley. I cannot figure out how it moved. Nothing seems loose.

I thought about replacing the clutch, pulley and coil but it does not seem as if they are bad. Perhaps the bearing is shot but it sounds smooth and there is no play so I do not see how it would shift forward.

It is a stretch belt for just the A/C. There is no tension-er on the late model Silverado’s. Nothing is locked up. The new belt was stretched up over the back lip of the pulley with about 3/4 of it still on the pulley. If it had run like that for long it would separate and melt just like the old belt. I took a couple of pictures and used a yellow saw blade for contrast as a straight edge. Could the pulley have moved and everything still feel solid as it should with no binding and no play?

There is a snap ring that holds the pulley in place so unless the bearing is not staked in place and it somehow allowed the pulley to come forward on it (probably closer to 1/4” instead of 1/8”) then I cannot figure out what happened. If that is possible and there is not anything else it could be I will get a puller and pull all that off and replace it.

Okay. Thank you. Time to get under the truck.

Chris

Ordered the parts. Will post the outcome when done.

Chris

Installed new A/C compressor coil, pulley, clutch. I used the shim from the old assembly (clutch was dragging slightly without it. Belt runs smooth. Unfortunately the A/C will not kick on the compressor. I checked the wire connector for the compressor with a test light and got no light with A/C controls on. Still not sure what caused the original A/C belt to be destroyed since everything seems to turn freely. The compressor is not locked up. Could it be a bad compressor even though the clutch turns freely. I visually inspected all fuses related to the A/C again and swapped the A/C control micro relay with the fuel pump relay (identical relay) with no positive results. The A/C control module switch illuminates but I cannot be sure it is not a bad switch. Before I buy a new A/C control module or pay upwards of a $1,000.00 to have a new compressor put in (or possibly some other issue) is there; 1.) A way to know if the compressor is shot? (I verified clutch turns freely already) 2.) A proper order to check wiring with a volt meter (possibly starting with A/C control module to fuses, relays and then to compressor)? I have a Haynes manual and think I know what wires to check on the wiring diagram, but I am not positive.

I have a gauge that came with a can of R134a that I used on my 1995 K1500. It connects to the low pressure port. Will that do?

Some slight pressure was escaping the gauge/hose at the low pressure fitting and the fitting past the gauge where the refrigerant bottle hooks up. The gauge was at zero.

Thank you Roy. I will see if I can find the leak.

Chris