Re: Oiling system history recap and update on the Oldsmobile oil pump conversion

Posted by humanpotatohybrid On 2024/4/22 19:49:05

Having picked up some copies of the factory drawings, I'm able to give some data:

Shaft dia was .4930 to .4935
Bore dia was .4950 to .4960
Note that this applies only to the driving shaft. The driven gear was on a dowel pin, 440601, which was a press fit into another .495–.496 hole.

You will note that this is a 1.5 to 3 thou drive shaft tolerance from the factory; yet no allowance past 3 was given in the service checks.

The two gears were identical except for the obvious differences and bore dia.

The gears when mounted in the pump have an end clearance per the factory drawings of 2 to 6 thou, yet strangely the service manual gives no more than 3 thou as acceptable. I have a 1953 and 1956 oil pump body drawing and this was not changed between them. My gear drawing is from 1953. Though both the "1953" drawings were revised through 1955 with no change in this regard. In addition I have another oil pump assembly drawing from 1956 that specifically gives 2 to 6. I can only assume they may have been selectively assembled to keep the gap down, but that would still result in a typical gap of 4.

The gear bore is 1.500–1.501 and the gear OD is 1.4945–1.6945. Again, the service manual gives no allowance for wear, specifying no more than 5 thou.

Hope someone finds this interesting and that the Studebaker museum enjoys my "donation". Let me know if you have any questions that I could look up for you. I don't have EVERY drawing just the most important drawings.