Speedometer too fast

[PaulPort64]

I have a 1999 Chevy Tahoe LS with a 5.7 4x4. Trans is a 4L60E . I’m looking for advice on a speedometer issue. The truck runs and drives perfectly in every way including 4wd. The issue is only in the speedometer. As I accelerate the speedometer is basically going twice as fast as I’m really going. I scanned the truck and the only issue that the scanner tells me is there’s no signal from the transfer case. I was wondering if anyone knows where I should start with this issue. Fuse panel says there are 2 spaces for the transfer case. #2 & #24. 24 is the only one that has a fuse . #2 can’t take a fuse, it’s blank. So I’m looking for options now. Thanks

 

[kennythewelder]

There are a ton of threads on here all ready on this subject. Here is one.
https://www.gmt400.com/threads/speedometer-calibration.51704/#post-1141765