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Just swapped out dash on my NB8a. JDM speedo reading 20kmh slower than actual speed.
Checked with gps on phone. I know not the most accurate, but very obvious difference.
Anyone else had this or any ideas on a fix?

If its 20km lower, not 20% lower then just pull the needle off and place it in the right position.

Dann

Check the difference at various speeds with something a bit more reliable like a real GPS, or hold constant speed for a good few seconds to get the reading.

If it's the same all across the range, then like Dann says, just shift the needle.

Otherwise, you might have to change the speedo sensor.

Thanks guys
Will be onto that 1st thing in the morning.
Defiantly 20k across the range up to 100.
Will post results tested with "real GPS"

Phone GPS will work but as you know, they are slower to react, so just hold speed for a few more seconds.

If it is a consistent 20km out, then it is definitely not the sender, but a static shift which needs the needle shifting round.

OK, I had a fiddle with the needle and got a result that I am happy with. Checked with both cheap phone and cheap GPS. I must admit, this is the most I've ever looked at a speedo. I do most of my driving on back roads in the Perth hills. So it is mainly driving to suit the conditions, I am just glad I have not stumbled on any speed cameras (yet).

Thanks again for the help

Good on ya mate. Glad to hear.

Dann

MazDaz66 wrote:OK, I had a fiddle with the needle and got a result that I am happy with.

Out of interest, did you take the needle off and put it back on, or just give it a bit of a shove?

I've always read that it needs to be taken off and put back on - but I managed to fix the fuel gauge on a new cluster just be giving it a poke to the right place.

Perhaps I got lucky, or fuel is a different type of needle or whatever...

Did both with the needle.
Pulled needle almost off the shaft, held shaft behind fascia with pointy nose pliers and moved needle.

Pulled it completely off the shaft. Found a quiet straight stretch of road, picked a constant speed and pushed needle on at that point.

wound needle by hand until it stopped and gently tweaked it a little more.

Being a bit over fussy trying to get it right.
Needle does not sit quite on zero when stopped, but who looks at a speedo when stopped.