Really Frustrated with Speedo

[svastano]

Group,

When I did my build I bought a new Speedo head and all seemed well until this spring. I had a gear change and went from 3:50 to 4:56 and then I changed out the speedo gear in the transfer case. I am running 36" tires. Long story short no matter what gear I have used I cannot get the speedo to read properly. And I have all the colors and teeth from 16 to 21. I am anywhere from 7-12 mph off and the needle is bouncing. I have a new cable and that did not help. I thought that there was someone on this board that rebuilt the heads but I am at a loss on what to try next. I tried using the chart that was posted but nothing works. Any help and advice would be appreciated.

Sam

 

[Master Chief]

Like you I went through several gears then I found this company and bought a gear adapter. It fixed the issue.

https://speedometercablesusa.com/

 

[bronkenn]

When I seen the title I thought maybe you were having an issue with the coverage that was afforded with the product....

 

[mrdrnac]

You said you changed the gear in the transfer case. You are talking about the drive gear correct? And you went to the drive gear that has 7 teeth? The 6 tooth gear won't work with your combination of tire size and axle gearing.

Also the bouncing reading is usually caused by a cable that needs lube, different problem than the speedometer reading wrong.