The Stovebolt Site Forums The Shop Area General Truck Talk 1962 speedometer guts

I changed the speedometer out in my 62 a while back. The original read the proper speed(before it decided to retire). I ordered a new one and it reads 10 MPH slower. My question is this... inside the old unit there are two gear shafts that still look like new. I wonder if I could put those in the new spedometer to correct the problem or if I just have to live with it? Any help from the wise elders would be greatly appreciated.

maybe the speedo gears in the tranny was calibrated for an incorrectly working speedo at one point in the past

Changing the gears in the speedometer should not change the way it reads. Should be the same. All old GM speedometers with the exception of 65-69 corvairs (if there are others, chime in) are geared to work with 1000 revolutions per mile input. With the speedometers all the same, changes were made in the gears in the trany. It is possible, however, that one of the two speedometers was not correctly calibrated.

I had a feeling that was going to be the case. Thanks for the help