Loud vibrating sound from compressor when aircon is switched on

[Honduh]

hi all

I have a question about an issue I am having with my air compressor. I tried to fix it recently when I did a radiator flush as I had to take the mudguard off.

Basically when the aircon is switched on a very loud vibrating noise can be heard. The belt is fine and turns fine when the aircon is not switched on.

After some tinkering I found out that the center nut on the outside of the compressor kept coming loose. I would tighten as much as possible, run the A/C, it would work fine for about 5 seconds (blow air and be silent) then would again start to vibrate noisily. Rinse and repeat and this is at least initial diagnosis of the issue. The belt is fine, is not loose and does not have any sideways movement when the aircon is engaged and being noisy.

So I am wondering is it an internal A/C issue which is loosening the outer nut, or does the outer nut need to be tighten with a rattlegun or something stronger than just a wrench?

I have browsed this forum for similar issues and come up empty.

Cheers

[bennjamin]

You need a special tool to hold the inner wheel while you tighten the clutch nut.

[Honduh]

I finally got around to trying that one but it still rattles loose, does not seem to vibrate loose but the nut just does not stay on.