rear end axle gears

[Chris H.]

I am thinking ahead to next year when I pull my rear axle and suspension out for restoration.

How do I tell what ratio I have if the tag is missing?

'62 340 hp

thanks

[William C.]

Re: rear end axle gears

the tooth numbers for the ring and pinion are stamped into the edge of the ring gear flange just read and divide 37-9 is a 4.11, etc.

[Frank H.]

Re: rear end axle gears

You can also check your stamped build code/date on the right side of the third member along with the casting number and date on the left ,in advance of opening it up to know if someone's been their before and better consider parts missing.

[Don H.]

Re: rear end axle gears

The easy way to tell what it is now is jack up the rear end so both rear wheels are off the ground. Mark the drive shaft and tire then turn the tire. Count the revolutions of the drive shaft to wheel. Slightly more that 4 turns of drive shaft to one turn of the wheel is a 4:11. Don H.

[Chris H.]

Re: rear end axle gears

I have not tried it yet but I assume I will have to turn both tires in the same direction.

Chris

[Don H.]

Re: rear end axle gears

Chris,
Do not worry if both tires are turning or not (posi makes a difference). As long as the tire and driveshaft are turning, it should give an accurate number. Not very scientific but it works. Don H.

[Tom P.]

Re: rear end axle gears

It DOES matter if both tires turn. If it has posi, then both tires should turn together. If it does not have posi, then both tires need to either be turned together, one turn, and count the number of turns made by the driveshaft. Then, the number of turns made by the driveshaft per one turn of the wheels, is the ratio.
Or, without posi, hold one wheel so that it does not turn at all, turn the other wheel one turn, count the number of turns made by the driveshaft then divide by 2. With only ONE wheel turning, the drive shaft will turn twice as fast.
FACTORY available ratios for the 56-thru-62 cars were: 3.08, 3.27(56 only), 3.36, 3.55, 3.70, 4.11, 4,56.