Gear choice for 02 grand marquis

[bigbadmerc]

I am just learning about gears and i need some information and some advice. I want to get either 3.73 gears or 4.10 gears. I have been told that for only lightly modding a car i should go with 3.73. are 4.10s to steep for a daily driver. will my car wind out to much at 70+ mph. Also i am not sure what else i need to make the gears work, chip to reprogram the tranny? Some one told me i will need a new aluminum driveshaft. Will my stock driveshaft work? i am on a tight budget. As you can see i am new to the performance side of cars so please let me know what kind of parts i will need for my gears as well as any advice anyone may have. thanks
-Bobby-

[GoodSamaritan]

Here's you answer... it depends.

First of all I would think an 02 already has the aluminum driveshaft.

If the car is going to see much time on the interstate, I would suggest 3.73's. They are just about the perfect compromise for a daily driver. True you will get worse mileage on the interstate, but not a whole lot. I am sure other members can chime in and tell you their experiences. You should gain a bit of mileage in town and have a very noticable improvement in acceleration.



If you are planning on putting huge tires on it (donks/dubs) then you need to get your head examined. If that doesn't help and you still are set on running 24" rims on all 4 corners, or rarely if ever take the car out of town, then you might want to go with something a bit lower. (numericly higher 4.11+)

Your first step is to look at the "AXE" code from the tag on your drivers door, and match it up to the one in my sig, to see what your existing gears are. Then tellme what size tires you plan on running. I can give you a comparison of what rpm,s you are running at a given speed now verses what rpms you will be turning at the same speed with a different gear.

Good luck.
Bryan

[bigbadmerc]

gears

Axle
C8

that is the axle code i found on my drivers door sticker, but for some reason it doesn't seem to match up with you model
my tires reads P225/60R16

I figure right now my car shifts from first to second gear at about 49mph, hopefully with the new gears it will blow through the gears a bit faster than that.

the main reason i am getting gears is to help my low end acceleration
i took my mercury to the track and ended up running 16.8 in the quarter mile
I am hoping with new gears my new gears I will be running around 16.4-16.6, but im not really sure if thats a realistic assumption
I am not concerned about gas milage I just want more power

Also what do I need to do so my speedometer reads accurately with my new gears?

thanks for all the help I appreciate it

[Grandmarchris]

Run a 3.73 or 3.55 if you are really concerned with gas mileage

[Johnnyiroc]

I have 3.55 now and average about 17mpg.....My 3.73s werent much different, If I had a choice I would go to 3.27 for mileage because i drive it 50 miles a day to wark and back, 60 a week in gas is sucking!

[Grandmarchris]

I think the C8 is a open 2.73 The best thing for you to do is to score a Traclok diff out of a wrecked Vic and most of the time you will get the gears you need and the diff you need cheap

[sdacbob]

I've got an 02 GM. I had 3.27's with a trac-loc and my around town and highway mileage was fine...20 around town and 25 to 27 on the highway. I have 3.73's now. My mileage has dropped to 18 in town and 22 on the highway. Part of this is the gas is now 10% alcohol. It sure has plenty of pep on the take off. You will need a black speedo gear and your speedometer will still be a little off. Your shift points will also be lower unless you get a tune. I have the MM airbox and MAF from an 02 Mustang GT and had the tune done for that. If mileage is a concern then go with either 3.27's or no higher than 3.55's.
Also your car has a steel drive shaft. If your use the police aluminum shaft you also need the tailshaft extension for the transmission. It IS recommended if you do high speed driving over say 90.