Originally Posted by funola

Kent, both R4's are OEM Mercedes Delco's afaik. The X does point to an oil hole.on the 4 bolt bearing plate. Since It's been removed, I couldn't tell it's orientation with respect to the compressor so I looked at my other R4, which ihas a different casting and does not have an X like the first R4. It does however, have a circle in the same location on the 4 bolt bearing plate, and the circcle is on top with respect to the compressor. Assuming the 2 marks are equivalent, the Merecedes R4's do have the bearing oil hole on top to allow grivity feed lubrication.