anyone familiar with Nippondenso AC clutches?

[sixto]

I removed the clutch from the 10P15C compressor in my 87 300D because the coil draws about 20-amps instead of the spec 4-amps. I removed the spring plate and the pulley to find the coil has a few mm of radial play on the compressor. The coil is held on the compressor by a circlip and positioned by at least one dowel and possibly a hub centric arrangement. The coil has 3 dowel holes but I only see one dowel on the compressor. The corresponding dowel hole on the coil is elongated either from vibration wear or improper fit. The inner diameter of the coil is a few mm larger than the tapered hub on the compressor. There's no way this is a hub centric fit if this is the right coil for the comrpessor. It appears the there is enough play in the coil that it contacts the pulley. There is more scuffing on the inner surface of the coil than the outer surface, and the same corresponding degree of scuffing on the pulley surfaces. It doesn't look like 230K miles of scuffing. If there is indeed contact between the coil and the pulley it didn't happen until later in life.

Question - how much radial play should the coil have when mounted on the compressor? I would think there shouldn't be more than a hair's width but I don't see the mechanism to accomplish such a close fit with the compressor and coil pair I have.

Thanks,
Sixto
87 300D

[loepke72]

I've dealt with these compressors before, and they are very similar to the Ford compressors. These have coils that fit pretty closely to the compressor hub. The three holes in the coil are most likely to allow the coil connector to be positioned in the proper location for the vehicle. The fit of the coil is more like a fraction of a millimeter, not several mm. You either have a worn compressor hub or the wrong coil. Compressor clutch parts come in different sizes and do not necessarily interchange on a particular compressor. I was once sent three wrong compressors for a Mazda MPV by a warranty comapny. They came in Denso boxes, but had the wrong clutch, and the one off the old compressor was too loose of a fit to just switch them over.