Re: '55 Oil pump shaft wear

Posted by BH On 2014/3/13 8:59:44

Hash pipe?!? Rather than draw the attention of the authorities with such talk, let's just call it a 'sump tube'.

That tube was promoted by the factory (see STB 56T-20) for field service of the early design pump WRT to lifter noise caused by low oil pressure. For some reason (and perhaps more than just warranty cost), they didn't want dealers replacing those with the late design pump that had been introduced in engine production.

The second design pump has the pressure relief bore threaded and plugged (with some other internal differences); the body casting number is 6492430. So, you definitely have the early design pump.

Dunno what to make of that spot on the shaft. Doesn't look like simple wear. That end of the shaft just slips into a socket in the bottom of the distributor drive gear. Did you inspect the mating part for any corresponding marks?

Meanwhile, with no load on the outlet side, I'd expect any pump that's capable of turning at speed to shoot a stream of oil.

Were you having a problem with the pump, lifter noise, or low pressure prior to its removal?