I have 2003 GMC Yukon XL 4x4 and I have been having issues with the speedometer on my SUV. When I’m driving and I accelerate the needle stops and steadily increase up to the max reading 140mph. What do I have to replace on the car? Is it the cable or the sprocket in the transmission?

it might be a bad conection behind the speedometer it self because a 2003 yukon is to new for somthing like that to be replaced

Just a suggestion/possibility here, as I have a totally different car. The needle on my speedometer stopped working last year. Just wouldn’t move at all. Turns out that there was a problem with the speedometer driven gear. Got that replaced and it has been working ever since.

More then likely you have a faulty stepper motor on your speedometer. Check out this link. I have bought 10 units from him and they have all worked perfectly.

This is a known problem for GMC’s…mine had the exact same thing. They had to replace the dash and fortunately mine was under an extended warranty. sorry