62 rear end gear ratio

[John A.]

I have a 62 that the tag on the rear end is missing however the number forged into the housing is K156 3725888. Is it possible to tell the gear ratio and type of traction by this number?

[Larry C.]

Re: 62 rear end gear ratio

No. Assuming it's the original Corvette rearend, there should be two letters and a few numbers stamped into the cast iron housing on the opposite side. The letters will indicate the axle ratio as presented in many Corvette publications. The numbers will be the date assembled.

[Larry C.]

Re: 62 rear end gear ratio

Further, the letters/numbers you indicated in your post are not indicative of a 1962 rearend. I would interpret the K156 to be October 15, 1966, maybe 1956. If the rearend is a posi-traction, there will be a large letter P on the side of your casting numbers. Pretty sure the casting number should be 3789812. Don't recognize the number you posted. Am sure there are more knowledgeable folks that can steer you with the correct information.

[Bill O.]

Re: 62 rear end gear ratio

John,

You might want to confirm the last numeral of the casting date and the last two numerals of the casting number...these aren't coming up "62 Corvette" for me.

Bill

[John H.]

Re: 62 rear end gear ratio

I have a 62 that the tag on the rear end is missing however the number forged into the housing is K156 3725888. Is it possible to tell the gear ratio and type of traction by this number?

John -

The casting number is probably 3725899, not 3725888; that would make it a '57 non-posi center section, cast on November 15, 1956.

[John A.]

Re: 62 rear end gear ratio

I think you are right... it' 3725899. Is there a way to determine the gear ratio?

[John H.]

Re: 62 rear end gear ratio

I think you are right... it' 3725899. Is there a way to determine the gear ratio?

John -

There's a ratio code (two letters) and an assembly date stamped in the rough as-cast area on the passenger side of the casting; hard to see, will require some cleanup. That will tell you what ratio was originally installed in that housing, although it might have been changed over the years.

Otherwise, jack up the rear of the car, mark the tires and the driveshaft, and turn both rear wheels one full revolution, counting the driveshaft turns; the number of turns of the driveshaft will tell you the axle ratio (3-1/2 is a 3.55, 3-3/4 is a 3.70, etc.).

[Bill O.]

Re: 62 rear end gear ratio

And If you are sure your speedometer and odometer are accurate, the color of the speedometer gear in the transmission will tell you which ratio its matched with.

Bill