I just put in Blue LEDs in the dash and before that I had put in regular blue lights. When I put in the blue lights, afterwards the speedo was off, by alot. Now that I switched the LEDs in I was real careful to try and get it back the way it was but it is still of, by alot. When the speedo says I am going 50 I am really about 85-90. Anyone know how to take care of this.
Brian

 

My speedo was a little off too, so this is how i fixed it.

I calculated the engine RPM at 60MPH based on the tire diameter, and axle ratio. I did not include the transmission ratio in the formula becuase used 3rd gear(automatic, 4th for manual) which is a 1:1 ratio. Once I found the engine RPM at 60MPH in 3rd gear, I removed the clear plastic lens from the gauge cluster.

Now here is the part where you have to pay very close attention so you don't get hurt. I put the car on a level, concrete surface and chocked the front and back sides of both front wheels so the car could not move. Then I jacked the rear of the car up by the center of the rear end and supported it with jackstands and removed the jack. Place the jackstands on the axle tubes as far outward toward the wheels as possible without touching the tires or suspension components.

Once you're sure everything is safe, start the car, put it in drive and slowly accelerate to the RPM that you calculated. You can set the cruise control at this point, but if you don't have it, then you can do it with a steady right foot.

Now, the wheels are turning at 60MPH, and the engine is turing at your calculated RPM, so carefully move the speedometer needle to the right, past the last rading until you feel it hit the stop. Apply a little more pressure until it moves a little. What is happening is the neddle is moving, but the shaft is not. Carefully return the needle to 60MPH and let go. Repeat this until you get it exactly at 60MPH. Once it is right, take your foot off the accelerator, or shut the cruise control off. Shift into neutral, shut the engine off and let the wheels come to a stop. Shift into park, and set the parking brake. From there, lower the car to the ground, and put the dash back together. '

This is probably not the recommended way to do this, but if you are very careful and use common sense, it gets the job done.

 

Wayyyyyyyy tooo difficult..

if you have the origional speedo and all you did was replace bulbs heres what you do...

look near the 5mph mark there should be a small dot/line below that... put your key in and turn it(dont turn the car on though) turn it so all your gauges reset .. pull out your needle and place it so that it points to the lil dot. thats all i do when i replace my dash lights.. hope i helped.