The attached photo shows a dismembered Bosch distributor (body/shaft/gear only) out of a junkyard 1989 245 wagon with B230F engine. The top and bottom bushes are steel, not sintered bronze,and the sections of shaft in the bush has spiral grooves. There are no felt pads soaked in oil etc. The "washer/spacer" next to the distributor body is actually part of the lower steel bush that was sawn through and prized out of the body. There is one thin washer on the shaft.

It seems that the lower bush is lubricated by engine oil spray/mist/fumes, but how is the top bush lubricated? By crankcase pressure forcing oil fumes up into top bush through the spiral grooves on the shaft?

If this is the original distributor - 19 years old - there is very little wear. I cant feel any sideways movement. There is about 20 thou axial movement up & down - certainly not packed with spacers to limit movement.

I ask this question as a spare parts man told me distributors on old cars must be rebuilt. By replacing the bronze? steel? bushes & shaft? And centrifugal advance plates? My 30 year old distributor (1979 240 with B21E) tests just within the upper and lower limit Bosch graphs (in Volvo green book) for centrifugal & vacuum advance. At 3000/3500 RPM there is + & - 3 to 4 degrees of timing "jitter" probably due to the shaft gyrating instead of pure rotation in the top bush due to some wear. Sounds like paying for distributor "service" is throwing money away.