Customer complained that vanes not opening. Found control shaft had galled against prv control shaft cover plate? Replaced shaft(new square end model) torgued to specs, pulled compressor bearing housing back to check vane operation and all looked good. Reassembled and placed back in service. 1 week later after sitting idle it started dragging again. Loosen up the 2 bolts securing shaft cover plate and vanes stopped dragging. Model YDHA90 compressor. Any one seen any service letters on this problem?