I have an 86 trans am and my speedometer is 10-15 MPH off. How would I go about fixing this problem? Also, my oil gauges dont work either. They dont move period. They just sit there. How would I fix this problem too? Thanks for your time.

 

For the speedo, perhaps the gear in the tranny needs replacing, especialy if you've changed your rear axle or wheel size.

http://www.700r4.com/SpeedOCalc/

For the oil gauge, perhaps the sending unit is dead.