'62 Rear Gearing Help

[David K.]

I am confused. The rear housing has the tag on that says it has a 3.55 gear. I just wanted to verify it, so I turned the rear wheel one full turn, but the driveshaft only turned about 1 5/8 turn. Something in my mind, doesn't add up here. What am I doing or thinking wrong here?

[Mike E.]

Re: '62 Rear Gearing Help

Probably turned 1 3/4 turns. Times 2 equals 3.50 Probably a 3.55--OR--what resource are you using for your information? I tag with no punches, cuts, or holes, is a 3.36, in spite of what Noland says. 2 X 1 5/8 = 3.25--could be a 3.36

[David K.]

Re: '62 Rear Gearing Help

I happened to have the Paragon catalog handy. The tag they sell for a 3:55 ratio is one round disc with the single hole for mounting. Same as I have on the car.

[Mike E.]

Re: '62 Rear Gearing Help

Then, if it is the original, it will turn just a hair past 1 3/4 turns to be a 3.55

[David K.]

Re: '62 Rear Gearing Help

Thanks, my confusion says one turn of the rear wheel would mean 3:55 or 3:36 turn of the drive shaft, instead of just half that number.

[Edward B.]

Re: '62 Rear Gearing Help

Try turning the wheel 10 times instead of once to improve the accuracy of your measurement.

[Gary C.]

Vendor tags all follow Noland's info

As Rev. Mike points out Noland's information on tags is incorrect for some unknown reason. And it appears the vendors all used the same information to make their tags from. Maybe Roy can shed some light on how/why this happened. Gary....

[Mike E.]

Re: Vendor tags all follow Noland's info

Gary--
There is GM documentation from earlier (about 59?) that indicates the 3.55 being unpunched. My knowledge base is primarily 61-62 (go figure!)and I've documented 100's of 61-62 Corvettes and passenger cars with the unpunched tag being for a 3.36. Did they change at some point (between the GM documentation and 61-62), or is the documentation in error? I don't know the answer to that one.

[Gary C.]

Re: Vendor tags all follow Noland's info

Mike, link to GM ECR9904 with tag and ratio info. Ratios in ECR are 12:37 = 3.08, 9:32 = 3.55, 10:37 = 3.70, 9:37 = 4.11 and 9:41=4.55 Always wonderered why they 3.55 tag wasn't shown. Orginally that 3.36 tag was misidentified as 3.55 Gary....

[Gary C.]

Corrected Vendor Rear Axle Ratio Tag Photo

Correction to Vendor Catalog Ration Axle Tags. Gary....

[Gary C.]

Re: Corrected Vendor Rear Axle Ratio Tag Photo

Not sure why the photo links didn't work - here's the links to them. Gary....

http://tinypic.com/view.php?pic=hs6oau&s=3 Vendor Catalog photo - corrected

http://tinypic.com/view.php?pic=t6f98h&s=3 GM ECR9904 drawing with correction

[David K.]

Re: Vendor tags all follow Noland's info

That makes good sense to me. This '62 is a very basic car. The dates on the pig fit perfectly with the car, so unless someone went in and changed the gearing inside, I really expected to see a 3:36 ratio. If they had went into the pig and changed the gears, many people of the time would not have put the tag back on, it would have just fell to the way side. The car is your very basic 250hp car.