Ok we all got sick of seeing these gear threads so this is THE official gear thread of gear threads. This should tell you mostly everything you need to know with gears. If a question you have, isnt answered in here ask and if it was and you post it, I will delete it because you are stupid.

What is the right gear choice for me?
Most people will tell you to go with 3.73s for v6s, 4.10s for 2v v8s, and 4.30s for 4v v8s. This is usually recommended for all Naturally Aspired engines, and even for the Forced Inductioned 03-04 Cobras. Nitrous injected, and supercharged, turbocharged vehicles usually yeild better results with smaller gears. There are countless ratios of gears available for vehicles but the most popular for us are 3.27s, 3.55s, 3.73s, 3.90s, 4.10s, and 4.30s. The numbers represent the ratio of the gear teeth to the pinion gear in the rear end. You can find this number by counting the teeth on the ring and dividing that number by the number on the pinion and that will be the gear ratio. The higher the number of the gear ratio, the more times your driveshaft will rotate per wheel rotation. 3.73 gears will rotate your driveshaft 3.75 times per one full turn of the wheel, and 4.10 gears will rotate a tad over 4 times per turn of the wheel. This is essentially a torque multiplier. With changing gears your rpms will change in each gear you are in, and I suggest looking at a gear calculator for your vehicle to pick which gear is best suited for you.
Gear Calculator : http://www.allfordmustangs.com/Detailed/608.shtml


What is needed for the installation of gears?
There are a few things that are needed to complete the installation of new gears. First you need the ring and pinion with the ratio of your choice IE 3.73s, 3.90s, 4.10s, ect. Secondly you need 2 quarts of gear lube. I suggest a fully synthetic lube. Some have Friction modifier in it, and some dont. If its not included youll need it to help prevent your gears from "chattering." You will also need a rear end bearing kit, or installation kit depending on the mileage and year of your mustang. If you have a car with higher mileage or you are just picky or have bad luck, id say go with the bearing kit. If not the install kit is fine for most people. You will also need either a reprogrammer to make up for the change in gears or the dallas speedcal to fix your speedometer because gears will throw this off if it is not fixed correctly. Lastly, you need someone with the knowledge and the tools to do the installation right. If you ask "whats involved in installing gears" than chances are, you cant do it. Have a professional do them for you. The price should range for the average consumer around 100-250 bucks, all said and done.

Note: If you have a 1998 and prior car you do NOT need a Speedcal or a Reprogrammer. Your speedometer is mechanical, not electronic. Therefore, you need to get the proper speedometer gear to match up with your gear choice. You can find speedometer gears, here:

http://www.steeda.com/products/speedometer_recalibration_gears.php

-Shambles

What do I get out of different gears?
As mentioned above, gears are a torque multiplier so it would feel like some soft of power adder was put on your vehicle. Most people can yelid on average of .5 seconds off your 1/4 time simply by changing your gears. You will also notice a lot of the serious mustang racers and NMRA racers with 4.30 gears are capable of putting themselves in the high 12s, with minor bolt ons, weight reduction, and drag radials, so that gives you an idea of what gears are really capable of with a good driver.

 

Topic is now open for discussion. Please stay on topic or I will be forced to beat you to death with my 3.27s.

 

I would concur completely with the gear recommendations above. The only things I would add is that if your 4V car doesn't see alot of highway time and you're serious about running well at the track. I would get 4.56 gears. This is the standard for anyone seeking max performance at the track.

The other thing would recommend is if your running a positive displacement blower (really only for 03/04 guys) I wouldn't run more then 3.73 gears. These 03/04 Cobra cars especially modified have enough traction problems as it is esp. on the street. Therefore you'd want to keep the Gearing close to stock if youre anywhere near the 500rwhp range (are there any 03/04's that aren't? )

Other than that this is a great thread!

DON'T FEAR THE GEAR!

 

very nice article. I had a ton of pics from my install I could've contributed but my hard drive crashed


the gear oil smells TERRIBLE.

 

sooo why wouldnt you put 4.10's on the v6?

 

I'd say it would make it top out way too fast.

 

I did some of the calculations with that calculator MattJ posted, how come my v6 is said to run better with 3.10 gears rather then 3.75 gears that they recomend? do they even make 3.10 gears?

 

If you are wondering what gears do read the following.

 

they do make a 3.08

 

You shift a lot more but you get yourself into 5th in a lot of daily driving. Chances are they CAN void your warrenty but they probably wont if they arent gonna be dicks about it. its not going to break unless its installed wrong.

 

Nope. You wont see any gains by adding gears.

 

You will most likely see a DECREASE of HP on the dyno (depending on the dyno setup). The reason for this because you are using a torque multiplication the RPM is met faster before the horsepower actually has a chance to overcome the rotational mass, which is the dyno itself. I guess it's kinda like it revs up too fast and the horsepower is used in keeping it spinning.

Usually it's a 1-5 rwhp loss

 

What matt said about 5th in daily driving is 100% true.

I'm in 5th gear goin 45..well the gears AND if I stay in 4th gear my exhuast deafens people

but yeah, I pretty much use 5th gear everytime I drive

 

Don't wanna steal your thunder but you most certainly DO need a speedcal in a 98 and older car. The different tooth tranny gear does not fix the speedo problem, especially in an automatic.

Adam

 

4.10 is nice - actually makes the car shift smoother in my 5spd - - would say 373 for v-6's - 4.10 for GT's and 430 for corbas (higher red line) !

 

IF you have a GT go with 4.10 - if its a manual and same is an auto... cobra 4.30 - anyway alot of you are probably concerned about traction... well I didnt belive this until I got it done but... the 4.10 actually hook up alot better than the stock 3.27... thats right... the car instead of chirp and lightly skidding actually squats and goes now... this is not to say that you can't smoke the bejesus out of your tires with ease.. but at a 2500-3000 rpm launch they car bites harder... I belive this is due to the increased torque and the properties of the rubber (stock tires)... I love my 4.10 - highway is a little higher than expected for my year.. but still AOK... about 2400 @ 70mph... but bad at all ... did it hurt my gas mileage? I commute alot.. and honestly I maybe lost 2-3 mpg... barely noticeable - BTW I was gettin 30-32 highway (full exhaust no cats and granny drivn @2000) its true however that 5th will be you new 4th gear... doesnt bother me - actually the 4.10 makes the car alot smoother shifting in my opinion and to save gas with the 4.10 here is the secret with the tremec 5sp... shift 1st to 3rd 5th all at 3000rpm - makes for pefectly smooth driving - less wear and tear and also better mpg.. also shop around for install prices .. i got the local mustang shop (harris racing in concord NC) to do mine for $200 including fluids and its perfect w/ no whine. the 4.10 is wonderful on the highway - 5th is like driving a actually fast car now - dump 3rd to chirp and scoot and 4th is probaly all you really need to do anyway... :bash:

 

I took my younger cousin for a ride the other day.. I got on it just a little, nothing major at all though... and she freaked out. I told her that I wasn't even going that fast but her response was "IT FEELS FAST!" and that's my new definition for 4.10 gears "IT FEELS FAST!"

 

What Mph AND RPM Does A Stock Auto 03 GT Shift At

 

Depends on the position of the throttle. the more throttle that the car is given, the more rpm it will go through before it shifts.

 

KK
um im trying to figur out how many rpms ill be doing on the hiway and in what gear if i put in 4.10s,3.90, or 3.73s

 

Um, Why do you have to wait until 45 to shift into 5th if you have lower gears than I do and a bigger engine, I shift at 40 unless I'm in a hurry and I only got a V6. According to the manual, best fuel mileage if you shift at 40 for my V6. If I had lower gears I could probably use 5th gear in town (30).

 

read the thread. i posted a calculator for that...
:wallbash:

 

im using it
i just want to find out when the **** car shifts!!!!!

 

 

It shifts at redline under full accelleration