88 chevy ok speedometer problem
 

I have a 88 chevy pk I replace the gears in the diferential from 2.73 to 3.73 but since I did that like speedometer is 25 miles above the actual speed in going. If i'm going 20 it shows that I'm going 45. Can somebody help me to correct my problem? The trans I have is a 700 r4 with electric vehicle speed sensor. Thank you for your time.

Take it in to a shop or something and they should recalibrate it for you. It happens anytime you change tire sizes or gear ratios, The 06 dmax is running about 6mph slower than what its goingf

not on an 88.....you just change the speedo gear on the VSS they have diffrent colors for diffrent changes you need to make ......hit up a tranny shop or the tranny tech at your local GM dealership they should be able to get you the info you need