Speedometer and odometer problems

[burn_your_money]

Ok, I'm assuming the issue is with my speedo and that I'll have to replace the whole unit.

The speedo reads about 30% too high (it says 130 when I'm only doing 100) but my odometer is bang on the money.

What part needs replacing?

84 Jetta

[8v-of-fury]

The needle is off on its orientation? It is consistently that much higher than every speed?

[burn_your_money]

The only accurate speed reading I get is 0. 50 reads about 65 and 100 reads about 130. I'm not 100% sure that it's quite that linear, I'd have to check it with my GPS again. Weird eh?

[Enslaved_Pickle]

Mine was off 15 too high after i modded my cluster, "i took off the needle" so i opened it up again and drove around for a bit with my gps and kept pushing the needle down until it read right. I had to brake off the plastic stop pin "early 90's mk3 cluster" and it points almost right down now but it reads 100% accurate

[Brianshayne]

Mine does that too, and the needle shakes in the low range. If I'm going 50, it reads 60, then stretches to about 15 off by 401 speeds...

[burn_your_money]

If the needle shakes that's usually an issue with the speedo cable binding slightly.

[hillfolk'r]

I've heard in mk1s anyways at least ,
sometimes a bad ground wire can allow grounding to try and occur thru the speedo head with disasterous results. It'll heat the springs and other delicate items in the speedo head.