OK, I've measured gear ratios plenty of times before but this is a new one on me. uzzled: The rear of the car is jacked up. Transmission is in neutral (not park). Yes, the front wheels are chocked. The ratio is how many revolutions the driveline makes to every ONE complete revolution of the rear tire, right? Drive line turns 3 times and the tire turns once the rear gears are 3.00, right? Both tries are off the ground but it doesn't matter since only one tire turns at a time - open rear end (not a posi). My driveline turns 1.4 times to every one tire revolution. Ummmmmmm? uzzled: The car is the 1966 Skylark (below) with the ST-300 transmission. It has stock O.D. tires on it. What is the typical ratio in these things? What do I have? Help?
the open rears will do that .... my 70 wildcat did the exact same thing (1 and 1/2 turns on the drive shaft to 1 tire rotation) i knew that was impossible when i opened mine up it was a 2.78 rear i have since installeed a posi carrier (still have the 2.78 gears) i hope this helped scott
Well, yes that helps! It confirms that I am, in fact, NOT losing what's left of my brain cells. Thanks for that. Do you suppose a 2.78 is what I could expect in this rear end?
You have to rotate BOTH tires exactly one turn, which is hard to do with an open rearend. Without posi, it is best to just lock one tire from rotating at all, and turn the other exactly TWO turns, and observe driveshaft rotation. In your case that would yield 1.4X2 or 2.8 turns, which is very close to 2.78:1.
