weird spedometer problem

[burnin240sx]

I’ve noticed that sometimes my speedometer is close to my actual speed and some times it seams faster then I’m going. From years of experience. I took it to the drag strip figuring that I would find out if I was just loosing it. And it seamed that my speed-o was dead on. Then on the way home I was watching the meter like an eagle. I noticed after I about 50 the needle will jump up 10 mph every once and a while. It lies to me when it feels like it. So what the heck could this be? Is the speedometer messed up? Because I’m sure the ECU is fine and it's working sometimes so it's not the gear in the transmission. So I assume it's the Speedo in the dash. Any one else have any other ideas? Maybe an easy fix other then replacement. Not that I’m not up for replacing the gauges. Cause if I’m going to be in there I’ll get some indaglow too. While I have the dash off for the re vinyl or tweed. I can't decide on what I want to do with the dash still.

[NISTECH]

you can replace just the speedometer alone,not the tac or other guages. that is your likely problem.

[burnin240sx]

are there any donar cars beside a s13 that i could use for a replacement speed-o. i may just do some tinkering and replace the speed-o with an after market since it goes over 110 mph too. probly imposable i'll find out when i get in there.

[burnin240sx]

i know the 89-90 tach is for the singe cam but does that year have any difrence with the speed-o(i'm assuming a big no here but it doesn't hurt to ask)

[NISTECH]

big no here. wiring and circuitry is different.