Hello fellow rotary drivers. I'm trying to fix a noisy AC compressor clutch on my 1985 GSLSE. It is blowing chilly air and the system works OK when running. When you shut the AC system off the AC clutch gets noisy. It obviously is not shimmed right as the gap is too large (clutch to pulley) and shimming will be required to get the noise to stop. This is a new AC clutch unit that was replaced 6 mos. ago, I need some info or a source for the shim set that could be used to get the right gap and stop the noise. The clutch was bought new from e-bay and is not original one but one that was specified to fit. Don't know part number. Can anyone suggest a source for these shims?
I am sure it is the clutch making noise, not the compressor.

 

Have you looked at or measured your gap between the pressure plate and pulley? Probably supposed to be something like .030? From your description, common sense tell me the pressure plate is rubbing on the face of the pulley as it spins, creating the noise. Might just be rubbing in one spot, possible due to a warped pressure plate or maybe not its seated correctly on the shaft. Is the woodrift key seated properly and not cocking the plate? I've saw pulleys which have gotten dented in the belt groove that created raised or "high" spots on the pulley face as well.

Removing the one nut will allow you to pull the pressure plate w/out breaking any hose connections or anything. With the plate off, you can look at the key, inspect everything for burrs or debris and check to see what size ID and OD a shim would need to be. Maybe your local hardware store would have some compatible thrust washers in small thickness's. (.005 / .010)

With the plate off, you can also lay a straight edge across the working faces of both the pulley and pressure plate to check to see if they are nice and flat. If needed, you could probably tweak the pressure plate a little to try and flatten it out which might create an even gap so that it doesn't rub when not engaged.

 

Exactly, the gap is too wide and is chattering when off, seems a bit wobbly. Do you know the ID/ OD of the shims? I'm gonna do just what you said and take the front plate off. I wonder if the motorcraft shim set will fit? Removing front bolt just takes it off right?

 

Actually, any noise caused by rubbing would be due to not enough clearance or too narrow of a gap. According to the book, the gap btw the pressure plate and pulley should be .016 - .028. I'm sure it would still grip at twice that much, but engineers will be engineers. In normal operation, the gap would only increase over time due to friction and wear, making it less likely to rub when not engaged.

That is why I wonder if something is possibly cocking the pressure plate somehow and creating an uneven gap to where its rubbing at some point when not engaged. I do not know the sizes or configuration of the shims without disassembling one and measuring. Yes, the center nut is what holds the pressure plate on, however it is also seated on the compressor shaft with a taper and wood drift key. The taper will help hold it and may require a puller or prying with a screwdriver along with some light tapping to get it off.

I'd rotate it by the 19m nut to check the gap first. Is it even all the way around? Does it look like it's in contact at some point?
There could also be some debris in between one of the three flat springs and outer plate. Could be a bent or broken spring too. I'd check all that out good first and blow it all out, seeing if you can get an even, consistent gap all the way around. If not, then remove the pressure plate for a closer look.