While I had my valiant up on the jack stands last week I tried to determine the gear ration by rotating the rear wheel. I ended up getting right at about 1 ½ turns of the drive shaft for 1 rotation of the wheel.

Is there a conversion chart for doing this. I was expecting the drive shaft to turn a few more times.

This is using a 7 ¼ rear on a 63 valiant.

Thanks,

John

If its not a Sure Grip or posi diff then I believe you double the turns at the shaft for every rotation of the wheel assuming both wheels are off the ground. You likely have a 2.76:1 ratio. I think if you put one wheel on the ground to keep it from turning you will get the full ratio. Someone can correct me if I'm wrong.

Open rear: Jack up one rear wheel. Mark tire. Turn (2) revolutions whilst counting driveshaft revolutions. A chalk mark on driveshaft or pinion helps.

"Sure Grip": Jack up both rear wheels. Mark tire. Turn (1) revolution whilst counting driveshaft revolutions.

D/W

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If it ain't broke, fix it!

I find it easiest to count U-joint caps. There are four of them per revolution, so I just count the number of U-joint caps that face the ground over the course of two (open) one (suregrip) tire revolution, then divide by four, thus:

16/4 = 4 = 3.91
14/4 = 3-1/2 = 3.54 or 3.55
13/4 = 3-1/4 = 3.21 or 3.23
12/4 = 3 = 2.93 or 2.94
11/4 = 2-3/4 = 2.71 or 2.76
10/4 = 2-1/2 = 2.45
9/4 = 2-1/4 = 2.26