Packard Forum Index » Pre-War (1899-1942)

I am not well versed on the prewar cars but just the obvious. Is the diff an open diff? or posi? Is the other wheel turning backwards while you do this? Are you doing the procedure alone? Could the spider and side gears be messing with you? Is there a fill plug or other where you can see the ring gear? Mark it with yellow rear gear pattern setup grease and do the same verifing the ring gear rotation then you will be sure.

No, it's not a "posi". they didn't come on the scene until after the Korean War.

As to multiplying by 2, trust me. Think about how the differential works and the spider gears and it should become evident! Hopefully someone else will take the time to explain it to you, I've got fresh now to shovel!

One thing I'm curious about is the choice of it likely being a 4.1. With the 2.12 result times 2 why would the ratio be the 4.1 (4.09 listed as a stock ratio) rather than another stock of 4.3.

The calculated result would seem to be closer to the higher ratio than lower or do the differential gears do something else that would make one automatically choose the lower of two close options.

HH, I guess a more precise measurement is needed, making sure first to remove all the slack from the various components. I wasn't aware a 4.3 was available so I was just guessing at a 4.1 (4.09) and assuming (I know, I know...) some imprecision in the measurement.

Ok, so I am a moron. It's 4.3:1 . Helpful hint for the impaired such as myself-if the result seems to be about half of what is expected, rotate BOTH wheels simultaneously and count the corresponding number of rotations of the driveshaft.