Hey, I've been reading up on how changing the gears in the rear can really wake up your ride. I'm going to play stupid just so you all can give a true response. What benefits will come from purchasing these gears for my car. Its a 2002 GT Mustang 5spd by the way. Will itthrow the speedometer off? I just want to be aware of what will come of these gears. Thanks everyone.

Mitch

 

*** i have never even popped the hood on amustang newer than '99 so i'll give basics and reference points


assuming you have a 3.08 gear , it would bump your rpms by about 750 at any given range once your going

the "leverage" you gain can be computed by rear end gear x gear = total gear

so a 3.08 geared car with 3.35 1st gear would have a total gear of = 3.35 * 3.08 = 10.31800

same car w/ 3.73's would be = 3.35 * 3.73 = 12.4955


now they say anything over 12 in 1st is pointless but 12 is optimum, but i can say from experience nothing beats 4.10's on a stockish car and i am all about the 4.10's, 3.73's are fine but just not enuff imo


now for mileage reduction......as soon as you start to jump it will drop, doing a single gearswap (like going from 3.08 to 3.27) is not even noticible as far performance but you might lose 1-2 mpg, jumping 3 sets i would guess you lose 3-6 mpg

i have 4.10's and get 21 mpg still on the freeway, '93 notch, 5-speed and i tach about 3000 dead on doing about 85


speedo ?? yes it will be off, i can't say from when...but some of the newer cars need to reflash the computer to make it run right, foxes simply need a 10 min $10 speedo head replaced , so i'll let a newer car guy tell you about that

bottom line, the 2 cheapest mods that net the best performance dollar 4 dollar are nitrous and gears, so do it

3-4 sets stepup will "feel" like another 75 or so hp under the hood

you'll love it, but may need sticky tires to take full advantage of it

 

Gears are the best bang for your buck

 

Thanks so much for the info. It is greatly appreciated. All the Best with your ride.

Mitch

 

ya youll love the gear swap, i think the 3.73's are perfect once you start adding power you dont need to have a ridiculous suspension to get traction off the line, and to answer your speedo Q, your going to need a hand held tuner like a Diablo tuner, it will correct your speedo its pretty easy to use.

 

I have 3.73s in my 98gt and i love em. alot of people recommend 4.10s but i would think they are just to short. 3.73s are the way to go, and it will through off your speedo abit like nitrous_bob said

 

if i get 3.73 gears do ineed a t-lok? whats up with the t-lok's anyway??

 

you already have a t-lok

you might require a rebuild....but thats no biggie

the clutch packs wear out or the carrier can break and make you a 1 wheel willie

 

this happened to my car, when i got on the throttle i could feel the back end starting to get out of shape. couldn't figure out what the hell was wrong until someone suggested the differential. i did a burnout while someone video-taped it, and only 1 wheel was spinning the whole time. i just upgraded to an Eaton posi and 31 spline Moser axles, since i plan on doing either supercharger or nitrous in the near future.

i've got a 2002 GT with the 5 speed transmission, and i love the 3.73 gears (your stock gears are 3.27 by the way). you'll definitely feel the difference, because of the extra thrust it provides (more leverage... imagine tightening a bolt with a short wrench compared to a long wrench.. the longer wrench provides more torque with the same force applied to it). you'll need to recalibrate your speedo, but you can do this with any hand-held tuner (i have the SCT XCalibrator 2). otherwise your speedo will show higher than the speed you're really going (plus you'll put extra mileage on your speedo, even though you're not putting extra mileage on the car). it's a worthwhile investment because the tuners also let you read check-engine light codes, and you can custom-tune your computer with them if you do future upgrades.

 

I will be installing my 3.73s sunday, I should have done it long ago... I am ready to feel the difference from stock gears