Packard Forum Index » Post-War (1946-54)

Peter, wouldn't two revolutions give you double the ratio? I've only done it with one, and got an exact reading every time.

I think Peter is using 2 revolutions versus 1 simply so that the driveshaft revs are 7 or 8 versus 3.54 or 4.1, making it a bit easier to get an accurate count.

Jim G

Hi guys, Two revs are required if one wheel is up because on the road, in a straight line with no friction issues, the tailshaft has to turn both wheels at the same time, that is, with a 3.54 ratio, the tailshaft has to turn 3.54 turns to turn both rear wheels once. If you jack one wheel up you have to turn the one wheel twice to turn the tailshaft over the equivalent. The spider gears in the carrier are geared one to one with the axles. I suppose with one wheel up you are turning a 90 degree corner. Try it, it works and it only takes a few minutes. Best regards Peter Toet

Yes, a differential divides by two with one wheel on the ground.