C1 & C2 Corvettes General C1 Corvette & C2 Corvette Discussion, Technical Info, Performance Upgrades, Project Builds, Restorations

Speedo problem

Thread Tools
 
Search this Thread
 
Old Apr 7, 2011 | 09:24 PM
  #1  
vt65's Avatar
vt65
Thread Starter
Safety Car
10 Year Member
 
Joined: Sep 2009
Posts: 4,142
Likes: 24
From: Simcoe Ontario
Default Speedo problem

i have a P/G in my '65 and my speedo reads to fast, says i'm doing 60 mph when it's actually doing about 45. Would someone tell how do i determine which speedogear I need to order to remedy this?? The rear end is stamped AS3 15 65 .... the AS designation appears to be for a 3:70 non-posi and it is a non posi, car was built on APril 06/65 would it be the original rear end?

Last edited by vt65; Apr 7, 2011 at 09:41 PM.
Reply
Old Apr 7, 2011 | 09:35 PM
  #2  
Bluestripe67's Avatar
Bluestripe67
Race Director
Supporting Lifetime
Active Streak: 60 Days
Active Streak: 90 Days
Active Streak: 120 Days
Liked
 
Joined: Jan 2002
Posts: 15,359
Likes: 2,728
From: Close to DC
C2 of the Year Finalist - Modified 2020
Default

The best info I can gather from my GM parts book calls for a green 22 teeth gear. Someone else recheck this please. Dennis
Reply
Old Apr 7, 2011 | 09:38 PM
  #3  
vt65's Avatar
vt65
Thread Starter
Safety Car
10 Year Member
 
Joined: Sep 2009
Posts: 4,142
Likes: 24
From: Simcoe Ontario
Default

thanks Dennis, i think it's a purple gear in there now
Reply
Old Apr 7, 2011 | 09:52 PM
  #4  
Nowhere Man's Avatar
Nowhere Man
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 54,142
Likes: 9,451
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Default

there was never a purple one. Like Dennis said it should be a GREEN 22 teeth gear
Reply
Old Apr 7, 2011 | 09:54 PM
  #5  
vt65's Avatar
vt65
Thread Starter
Safety Car
10 Year Member
 
Joined: Sep 2009
Posts: 4,142
Likes: 24
From: Simcoe Ontario
Default

great that's what i'll order,,, thanks again
Reply
Old Apr 8, 2011 | 09:19 PM
  #6  
vt65's Avatar
vt65
Thread Starter
Safety Car
10 Year Member
 
Joined: Sep 2009
Posts: 4,142
Likes: 24
From: Simcoe Ontario
Default

pulled the gear today it was a red 21 tooth, i think with the big difference in mph between the speedo and my GPS i have to go with a black 23 or yellow 24? I'll order all 3 and see...thanks again for the replys
Reply
Old Apr 8, 2011 | 09:30 PM
  #7  
Nowhere Man's Avatar
Nowhere Man
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 54,142
Likes: 9,451
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Default

My parts book says for that axle ratio and stock tire size 22 teeth is all you need
Reply
Old Apr 8, 2011 | 09:34 PM
  #8  
Willcox Corvette's Avatar
0Willcox Corvette
Former Vendor
 
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Default

Originally Posted by vt65
pulled the gear today it was a red 21 tooth, i think with the big difference in mph between the speedo and my GPS i have to go with a black 23 or yellow 24? I'll order all 3 and see...thanks again for the replys
This might be a drive gear thing since there is such a wide variance.

While I always try to use the correct specified gear for a car, you can use as a rule of thumb 5 mph per tooth.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Best & 5 Most Overrated Corvette Track Packages of All Time!

 Joe Kucinski
story-1

Every 2027 Corvette Engine Explained

 Joe Kucinski
story-2

Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

 Verdad Gallardo
story-3

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-4

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-5

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-6

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-7

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-8

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-9

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
Old Apr 8, 2011 | 09:40 PM
  #9  
vt65's Avatar
vt65
Thread Starter
Safety Car
10 Year Member
 
Joined: Sep 2009
Posts: 4,142
Likes: 24
From: Simcoe Ontario
Default

Originally Posted by Willcox Corvette
This might be a drive gear thing since there is such a wide variance.

While I always try to use the correct specified gear for a car, you can use as a rule of thumb 5 mph per tooth.
thanks for that !
Reply
Old Apr 9, 2011 | 02:09 AM
  #10  
Willcox Corvette's Avatar
0Willcox Corvette
Former Vendor
 
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Default

No problem.. Hope you narrow it down.. with three to pick from you should nail it.
Reply

Get notified of new replies

To Speedo problem





All times are GMT -4. The time now is 05:59 PM.

story-0
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-1
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-2
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-3
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-4
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-5
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-6
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-7
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-8
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-9
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE