Possible causes of this mechanical speedo issue?

[deezdad]

As you can see its a sw mechanical speedo installed in a gnx repop dash cluster, connected to a new speedo cable for the application. Could it be as simple as the speedo being bad or out of calibration? Its brand new from gn restorations.. All opinions welcome thanks

 

[1KWIKSIX]

I'd guess the wrong plastic gears in your transmission.
What transmission is in your car?
What colour plastic gears (2 of em) do you have ?

 

[mikestertwo]

Need more info. I'm assuming the Scanmaster is correct? Have you verified that? Are you using a separate pulse generator for speed data going to the computer or does the speedometer have an optical sensor in it? If the Scanmaster speed reading is correct then the speedometer needs calibrating. Another possibility is the speed sensor is wrong and you have the wrong gear in the transmission. Need to know your setup.

 

[deezdad]

Thanks guys car is not with me I will try to get your questions answered..

 

[Steve V]

All gears are correct-this is the world of motorsports dash---I will add that the needle on this speedo does not sit at zero when vehicle is not moving. So at this point it is a cable or speedo issue.

 

[Steve V]

Need more info. I'm assuming the Scanmaster is correct? Have you verified that? Are you using a separate pulse generator for speed data going to the computer or does the speedometer have an optical sensor in it? If the Scanmaster speed reading is correct then the speedometer needs calibrating. Another possibility is the speed sensor is wrong and you have the wrong gear in the transmission. Need to know your setup.

Speedo was modded by Russ at GN Restorations for the vss pick-up. Scanmaster is correct. Gears are correct in the tranny.

 

[Steve V]

I will ad that I have been in contact directly with Russ. Speedo is going back for a refund and I am moving forward with GPS/electric speedo this week. I have been at RCG all weekend and have a solid game plan. Deezdad will be taken care of.