When i bought my car (1986 mustang gt 5.0 5spd) it had a 16 tooth gear in it, it wasnt even close to being accurate so my dad bought me the speedo gear kit with the 17,18,20,21 gear set, ive installed all of the gears and none of them have been accurate the closest one was still off by 20mph high and that gear was the 18 tooth gear. im stumped i looked at the charts, i dont have the ability right now to pull the rear apart and count the teeth, due to work school and other problems. is it possible my gauge cluster is just bad? or could the cable be shot?

 

if the cluster is bad you know what I'm gonna say

 

yeah yeah yeah....but is there anyway to test the cluster?

 

have you considered the gear inside the transmission is wrong/broken?

 

yeah!! but you don't wann hear the answer to that one!!! lol, use my known good one
if the problem still persists with my known good one the issue is either on the gear on the output shaft or cable, but I doubt the cable is bad

 

how do you know if the cluster is bad? i pulled my dash apaprt because my lights went out and now my speedo is off

 

make sure you got the cable snapped back in all the way

 

what rear gear is in the car?

 

no clue bought the car never touched the rear

 

Jack the car up, spin the tire ONE complete revolution & count how many times the drive shaft spins and you have youre rear gear ratio....make sure to put a couple of jacks stands under....you might have some low gears in there!