These things have gotten expensive from GM. Anybody got a used one to sell me? For my 91 RS.

re- route your serp belt.

Thanks for the reply. I did that like 6 weeks ago and I am having constant belt vibration issues. That long stretch between the crank pulley and the AC shakes and makes a ton of noise. I've tried 3 different belt lenghts.

I also tried going from the water pump to the AC, but I can't get it to clear the tensioner. Again tried 3 diff belt sizes.

wierd ... EBAY!

They're even worse on EBAY. people are asking like $80 on ebay!

I just used a shorter belt. Not sure if 84 engine is diff than yours. I would say the same.

Short belt, long belt, it still vibrates...

consider doing test with shorter belt and by passing AC ? maybe bearing in compressor shot? Just a thought.

Ha! Maybe if I lived in Wisconsin...It is over 90 and humid from April to late October here in S. GA. AC is the single most important part of the car.

Thanks for the idea though.

Just gut the vanes on the air pump. Can't remember exactly how I did it, but open it up and remove the vanes so that it is not pumping air anymore. Effectively, it will not cost hp to turn since it is not compressing air.

Did replace the two air pump bolts? IIRC, at least one goes into the engine block through the AC/Air pump mounting bracket. If you did not, it is possible the other mounting bracket bolts have loosened.