Hey guys, about a month ago I had a new rear axle put into my car, with a bigger ratio. I cant exactly tell you what the ratio on is because someone lost the paper on it. But to the point, after that my speedometer started showing speed the speed higher then I was going i.e. I am going 30 it showing 40, and if I am going 50 its showing 70. I am not sure what the problem is, but since axle was the last thing done to it I figured it had something to do with it. Any one had anything similar to this?

 

Same problem when i swapped in my 4th gen Camaro rear. Problem is that the gears for you speedometer are set up for the stock ratio that came in your car. You need to find out what ratio gears you put in your car and replace the speedo gears with the corresponding ones to your ratio axle.

 

So I am guessing 3rd and 4th gens didn't use the electronic speedo's. Any ideas where I can get the right speedo gears?

 

No, they do use electronic speedos (actually from 87 up firebird and 89 up (I believe) camaro is electronic speedo). But, the sensor is basically an electric motor, except it sends a pulse to the speedometer/computer every time a magnet passes by a switch on this rotating assembly (or similar principal). This rotating assembly in the sensor is driven by a specific ratio pair of gears.

Look for gears at www.transmissioncenter.net

Find out what your rear end ratio is, and calculate the gears you need.