A simple question with no straight answers, as it seems.

Does the old style (-1990) expansion valve have to be changed when converting to R134? Or, rephrased: Are there two different valve types, exclusively designed for R12 and R134 respectively? I know an old valve should be changed when you get in there but that´s another story...

The ball bearing conversion of my blower motor went perfect, btw. Nowadays I only listen to the sound of cold air coming out of the vents...and position 1 is enough most of the time. The conversion required something like one hour in the garage and two (SKF) bearings at $4 each.

Also noticed that the motor (80's style with tre mounting ears) had felt rings around the original bushings. Two older motors (70's, in sheet metal enclosure) I disassembled didn't have these rings. Guess that would be a significant factor for success if you try to lube an old motor to get rid of the noise - the oil or grease just won't stay for long in the older style motor but I think the felt rings will keep newer motors lubed for a pretty long time. That could explain the varying results from lubing reported here and elsewhere.

/Martin