AC compressor help

[Slonaker]

The compressor that you and I have (R4, I think...) is known for vibrating and making a moaning sound at idle. Mine has always done it.

Somewhere I have a copy of a bulletin from Chevy with instructions for fixing the moan, but it was considered optional if the customer wanted to pay to have it done. I think it required changing out the clutch, but I'm not sure.

Slonaker

EDIT: I have attached a copy of the three bulletins I have on the topic in PDF format.

[HTX86chevy]

OK, I MADE A QUICK VIDEO OF THE PROBLEM, SO THAT YOU GUYS CAN HAVE A BETTER UNDERSTANDING OF WHAT IS GOING ON BECAUSE I CAN'T SEEM TO FIND AN ANSWER. THE A/C BLOWS COLD. CLUTCH IS NOT STOPPING & STARTING, AND I DONT HEAR ANY CLICKS OR GRINDING.....

HERE IS THE LINK TO THE VIDEO:

http://www.youtube.com/watch?v=oFL81TrkUAw

CHECK IT OUT AND LET ME KNOW WHAT YOU THINK.

THANKS GUYS.

[blargh22]

I am having the exact same issue in my '88 suburban. I tried to tighten the belt but the issue still remains. I do suspect its a belt issue, as once hot it does seem to not be as tight. The AC is not blowing very cold, and I put 80% of 5.25 lbs of R134A in it, with about 8-9 oz of oil. It is blowing cold, about 60 degrees on a 100 degree day, but that does not really cut it in this weather. Is that normal for an R4, or should I be getting closer to 40 degrees?
The evaporator does get cold but doesn't feel ice cold to me. I was wondering if you ever got the issue resolved with the belt or not? I was planning on replacing the compressor. The compressor makes a lot of noise when in gear, but is quieter at idle. The belt vibrates a hell of a lot though, and the performance of the air conditioning isn't very good.

[Desert1957]

normal R4 operation , tighten all compressor mounting bolts