Alright well I have an 03 Evo 8 with an 05 5 speed shep transmission with stock gearing.

I noticed that below 65 the speedometer is pretty accurate according to my phones GPS, but the faster you go the more in accurate it gets. For example, 4th gear at redline, the car says I'm only going 103-104 approx and redline in 5th says about 145ish which I know for a fact is way off.

Anyone else have this problem? How did you solve it and does anyone know where I can get a new guage cluster?

Here is a pull I recorded last night, here it is. http://www.youtube.com/watch?v=Rnj4pfXuIPY

 

uhm, dont think checking it against a gps is very..."accurate"

 

Well since I first tested it on my friends 05 Evo 8 and found it to be right on par with his speedo I think it is.

Reguardless of what the GPS says, the speedometer is obviously off and by a lot.

 

than i would imagine bad sensor , or bad ground.....doubt its the clsuter...i have sorta same issue with my civic...except no matter how fast i'm going under 40...it will always say 40mph...and sometimes it works..dosen't bother me though as i never speed in that car.

 

First thing I would do is to test your speedometer accuracy. Your Mits dealer can hook your car up to the Medic (MUT3 scantool) and "dial in" different speeds and compare them to your speedometer reading. If there's a difference between the expected speed reading and the actual reading on your speedo, then you have a speedometer problem. If your speedo reading is accurate, the problem will be in your vehicle speed sensor circuit. You mentioned that your trans has stock gearing? Doesn't Shep give their transaxles a 4.11 final ratio that's not stock?