Looking at the back of the gauges you'll see two holes with the adjustment teeth in view...You use a small flat screwdriver and adjust those teeth up or down depending on which way you need to fine tune the needle sweep...Look at the gauge and see how it actually operates and then you'll see it's a fairly easy task...If you adjust one side too far the needle will sweep up then bend out as the fulcrum effect will be out of sync...So move it in small increments if at all...Take your time...I know it's a pain taking the dash apart but for the best accuracy I run the car with the sending units in place and have a second gauge that you know is correct to compare the values then adjust the rallye gauge accordingly
With that being said...If you did'nt have any problems with the gauge chances are you don't need to adjust it at all....
