Speedometer reads 15mph when car is parked

[ZCore]

My speedometer is off by like 15mph. It sits at around 15mph even when the car isn't moving. Anyone know what to look for to fix this?

 

[Buick Mark]

You'll have to re-zero the speedo. I had to do it to mine, but dont remember exactly how i did it. The tiny coil spring thats attached to the needle gets stretched from the needle in our cars being pegged at 85 or 90 mph just from passing in city traffic Its not at all hard to do, just a bit tedious. Mark

 

[ZCore]

Will I need to buy a new part? And if so anyone know the part #? Thanks in advance.

 

[ZCore]

Will I need to take apart the whole dash?

 

[Buick Mark]

You wont need any new parts, and you dont have to remove the whole dash, just the speedo cluster.
Remove the speedo bezel, then remove the tiny fasteners that hold the speedo cluster in place, If I remember correctly, the digital tach and boost guage stay in place, but you have to weasel the speedo cluster out from behind it, I wish I could remember better, but its been about 5 years since I had mine out.
The biggest thing to be carefull of is the speedo parts are somewhat delicate, they dont take too kindly too ham fisted people If you know somebody that had theirs apart before, see if they can help yah. If you were in the area, I'd do it for yah, maybe somebody will chime in. Mark

 

[ZCore]

Mark, thanks for the reply. I'll give it a try and see what I can accomplish. Who knows after i get down i may be doing 85 sitting still haha

 

[Buick Mark]

One other trick, disconnect the speedo cable from the cruise control under the hood. You'll see where the cable comes thru the firewall and connects to the cruise unit. This way you can gently push on the cable from under thehood, then pull gently on the cluster from in the car (kinda like a push me pull me!) This way its easier to depress the metal clip that holds the speedo cable on the back of the cluster. Just take your time, and work gently. As you go along you'll probably find stuf that I forgot to mention. Good luck to yah, Mark

 

[ZCore]

Ok hey Mark I finally got around to trying to do this. I've got the cluster apart and I am to where I can see/touch the speedometer needle. Do I need to take this out too? Or am I supposed to work with it from here?