Help me figure out my rear gear ratio.

[ComfortablyNumb]

I put the AOD in first gear and let it run up the tach to 4000rpm at which the speedo said I was going 60mph. I thought that was kind of high and that either my speedo is messed up or i have a really low gear ratio in the rear. I have 225/55/16 tires which is 25.74 inches. I dont know what the AOD 1st gear ratio is, which is really all I need to figure out the rear gear ratio. Can someone help me out?

Sorry if this question has been beaten to death. I cant jack the car up and spin the tires to find out the ratio, because I'd have to do it in the street.

 

[super302]

you got up to 60 in first gear??

 

[5spd GT]

Have you messed with the speedo at all...new guages????...something isn't right...speedo gear could be wrong gear...etc...???

 

[Euphoric306]

no, he was actually in second gear, cuz when u put aod in first, itll only go to first gear if youre going slow enough. 60 @ 4000 sounds about right for stock gears, i top out at like 78 or 80 at ~5000 rpm with my aod in second (first, whatever u wanna call it)

the for sure way you can find your ratio is by jacking up the back end, but ur street issue kind of sucks. dont you have a garage, and if ya do, why isnt ur stang already parked in it!?!?

 

[5spd GT]

Yeah...it it shifted into second...then that is about right...if not right on...

 

[302RWP]

How can you find your gear ratio by jacking your car?

 

[Euphoric306]

long complicated process, jk.

jack up back end, put car in neutral with ebrake off. make a mark on your drive shaft and rotate tires once. however many times the mark passes a certain point is your gear ratio. (3 and a half times = 3.55:1 gears, just over 4 times = 4.10:1 gears, etc...)