Bizarre Vacuum Pump Damage - seizing I-shaft

[Fatmobile]

How's it look down where the gear is pushed up against the pump body?

[the vegenator]

Well, the gear on the shaft itself looks fine, as does the intermediate shaft. There is some wear though on both the male end of the oil pump shaft and on the female slot of the vacuum pump. Seems like this type of wear is normal though.

When I installed it without the cover on, I rotated the engine by hand just to make sure it was spinning freely and the vac pump wasn't getting pushed upward. Everything felt solid. Only time will tell.

[Fatmobile]

When the gear gets pushed by the intermediate shaft gear,
it shoves the vacuum pump shaft upwards.

The top of the gear is pushed against the vacuum pump body,
I concider that the normal thrust surface/bearing and am wondering how that area looked on the damaged pump.

[rabbit_man]

I had the same problem you describe only I didn't run it 'til I lost oil pressure.

A month or two ago I tried "upgrading" my rabbit to the vane style vac pump but I never got it to vacuum right and when I took the cover off there was aluminum filings inside it.

The way it works is oil is pumped from the oil galley in the block into the oil pump shaft via a hole in the bearing and a hole in the shaft, from there it runs up the shaft into the bottom of the vac pump and lubes the rotating assembly where it rubs the cover, it also pushes the vanes out against the sides and lubes them for a good seal.

Something is wrong with my rabbit and it won't consistently pump oil out the top of the oil pump shaft. I verified this with a socket/drill spinning the oil pump. I think the bearing may be spinning thus blocking the hole from time to time. You might be getting the same problem.