My 92 pickup broke the vulcanized damper material in the A/C clutch contact hub and quit. Years ago, I could order just that part and change it out without wasting the R12 in my system.
Now you have a choice between a $250 compressor or a maybe fit $35 7SBU16H contact hub + $34 shipping from Germany. I did what I used to do in the shop to get a doctor or mogul's car cool again.
I put one in from the shelf of orphan compressors. Now the compressor runs continually. Did these have shim washers to space the contact surface from the factory? What did I do wrong ?

 

Solution; Thin and a wavy 6mm washer balanced on the center bolt as the disc was installed onto the shaft. No loss of freon.

 

Yes, there is a shim. Iirc Toyota had three different thicknesses.