Need recommendations - Speedometer
Thread Starter
POSSE ZR-1 Driver
Joined: Feb 2002
Posts: 3,980
Likes: 138
From: Groton CT
Need recommendations - Speedometer
I need some recommendations for Speedometer and tach calibration.
The Speedo used to read correctly until I replaced the worm gear for the odometer. Now reads much slower than reality.
Thanks in advance.
The Speedo used to read correctly until I replaced the worm gear for the odometer. Now reads much slower than reality.
Thanks in advance.
Instructor
Joined: Jul 1999
Posts: 235
Likes: 20
From: Albuquerque NM
If you want both to be accurate start by using which ever worm gear will give a reading as close to ten miles on a known ten mile stretch of interstate as possible. Check this a time or two on another ten mile stretch. When you achieve this remove your speedo and deliver it to a shop for cleaning/calibration. This should do it. Bill
Thread Starter
POSSE ZR-1 Driver
Joined: Feb 2002
Posts: 3,980
Likes: 138
From: Groton CT
Subfixer,
If you want both to be accurate start by using which ever worm gear will give a reading as close to ten miles on a known ten mile stretch of interstate as possible. Check this a time or two on another ten mile stretch. When you achieve this remove your speedo and deliver it to a shop for cleaning/calibration. This should do it. Bill
If you want both to be accurate start by using which ever worm gear will give a reading as close to ten miles on a known ten mile stretch of interstate as possible. Check this a time or two on another ten mile stretch. When you achieve this remove your speedo and deliver it to a shop for cleaning/calibration. This should do it. Bill
I'll answer the obvious questions....
The Speedo worked correctly, then the odometer broke. Speedo still displayed correct MPH.
I fixed the odometer problem, now Speedo mph is wrong.
Did not change gears in transmission.
Did not change rear ratio.
Speedo cable is ok.
Just need recommendations for a good shop that can calibrate these old instruments. None local to me.
Last edited by Subfixer; Dec 15, 2015 at 06:54 PM.
Melting Slicks
Joined: Apr 2010
Posts: 2,142
Likes: 282
2018 C2 of Year Finalist
2015 C2 of the Year Finalist
It sounds like you're down to adjusting the speed cup hairsprings and gaussing/degaussing the magnets.
I know there are a lot of shops that can do it, but I only have personal experience with the one that did mine. I used Corvette Specialties of MD West and had excellent results. They calibrated both my tach and speedo as part of a more extensive refurbishment. They weren't cheap, but nothing associated with these cars is cheap.
I know there are a lot of shops that can do it, but I only have personal experience with the one that did mine. I used Corvette Specialties of MD West and had excellent results. They calibrated both my tach and speedo as part of a more extensive refurbishment. They weren't cheap, but nothing associated with these cars is cheap.
