nikh23

Alright well the problem is that ever since I bought my car my speedo has been off. Its not off by a constant number, it just gets exponentially large as i go faster. Lets say the speedo says i'm doing 20 mph, i'm actually doing 25 mph, if it says 45 i'm actually doing 59 and so on. I have the stock tire size, stock rims, and stock 2.73 gears. I looked in the tech articles and found this part number 25513044 for the proper speedo gear size. Will this part fix my problems and if not what else shoudl i check. And lastly if this is the part that needs replacing how would i go about replacing it? Thanks for any help

25THRSS

Yhe previous owner probably installed gears and didnt change the speedo gears to go with it. The speedo gears should fix your problem.

nikh23

i'm pretty sure i still go the stock 2.73's, but in case i don't how would i go about finding out which gears he might have put in?

v8unleashed

iTrader: (3)

changing gears is going to make the speedometer read HIGHER than what you're actually doing, NOT LOWER.....and i doubt the previous owner put a lower ratio in, i dont even know if you can

so unless he changed the rear AND the speedometer, then changed the rear back, gears are not your problem

i would look at the speedometer guage itself

25THRSS

Thats true, you might need to have the speedo calibrated or just get a new one from the junkyard or ebay.

nikh23

how can i go about calibrating the speedo? Can it be done at home or would i have to take it to a shop

v8unleashed

iTrader: (3)

when i was in search of my speedo gears i went to one shop and the guy told me that i had no idea what i was talking about, there was no such thing as speedo gears and he had been in the business for 20 years and knew more than some "kid."

anyway, the point is that he quoted me a $150 price to "calibrate my speedo." apparently they put it on a lift and get it exact. if i were you i would first figure out what is the culprit. you dont want to spend gobs of money on nothing. but i dont know enough about how the thing works to advise you.

Dave Y

the trans may have been replaced with one from a car with 3.08 , 3.23, or 3.42 gears in it, the would make the speedo read lower than vehical speed, go here http://www.700r4.com/SpeedOCalc/ to find out witch gears you need(tooth count)
then go here https://www.thirdgen.org/newdesign/faq/thirdgen.shtml and find out what color they are, then check yours

v8unleashed

iTrader: (3)

oooh, i never thought of that


BUT now that i do think about it, all of the common ratios (3.08, 3.23, 3.42, 3.73) do not make the speedo read .76 ..... 3.42 is .79 and 3.73 is .73......that is if im thinking about this right

Dave Y

I would think that a couple of points off is within the normal range, do to tire wear effecting diameter, manufacturer differences and pressure

Dave Y

y

v8unleashed

iTrader: (3)

nikh23: are you 100% SURE it says you're going 20 when you're going 25 (80%) AND at a different time it says you're going 45 when you're going 59 (76%).

because if that is the case, it definitely has nothing to do with speedo gears and your rear end.

nikh23

i'm fairly certain, i noticed the 25 mph thing first when i was driving behind my dad in a 25 mph zone, my speedo said 20 mph and when i asked him how fast we were goin he said 25. And the time i foudn out i was doing 59 was in a 45 mph zone when i got pulled over and that was the speed the officer quoted me, the speedo might have said a little lower like around 42 or 43, not entirely positive.

i guess when i get home from school i can have someone drive in front of me hit and i can measure my speeds that way and i can post those numbers