This quote is from DIY on the gage cluster panel mod, and I was originally educating myself on this particular DIY. However, Richard’s comment (#2 Speedometer) caught my attention.
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Would this also be a good way to correct those speedometer differences with bigger / smaller tires than OEM's? I see why not tho.Taking pictures helps. Do this before taking your gauges apart
1) Tach= Drive your car around and let it warm up a bit. Make sure to remember at what RPM your car idles at.
2) Speedometer = This one is a *****.. I'll get back to it
3) Fuel= Empty your tank and remember where the lowest point is. Then fill your tank and also remember where the highest point is
4) Temp= let your car warm up and remember where it is
Put your gauges back together but not the front plastic
1) Tach= let your car warm up and gently put your needle in the right spot (never turn the needle, just put it on/take it off gently until you get it right)
2) Speedometer = PITA. What I did was late at night I got on the freeway and used the GPS/speedometer from my iphone. I drove for a few miles with cruise control and aimed for 70mph on the GPS. Once you are sure that you have been on the road for a long time Carefully place the needle on the dash (yes this is dangerous tricky to do when driving, make sure it's a straight part of the freeway and be careful). After this, change your speed (65mph, 75mph, 80mph) and see if the speed on your speedometer is equal to the speed on your GPS. This will take you some time to get right ( did it on two separate nights just to make sure).
3)Fuel= I found that the top of my fuel gauge was more accurate than the empty portion. I filled my gas tank and place the needle in the right spot
4) Temp = Warm your car up and then just place the needle in the right spot