ok, right now my 2006 reg cab 4x4 v10 auto has the stock 265 tires on 17" wheels, it has 4.10 gears, plow springs up front and f350 blocks out back

i just bought some 315-70-17 H2 take off bfg all terrains for 175 bucks and i will have them mounted this week.

im torn between 4.56 and 4.88 gears for this thing. i can setup gears no problem...i just dont want this thing spinning to hard. Im leaning toward 4.88;, but i dont know how i will correct my speedo since evidently ford cant even adjust them?? what gives?

iva already done all the calcultations and with 4.56's and these 34" tires it would be like having 415 gears with my current tires which would pretty much correct my speedo, with 4.88's it would be like having 4.45's with stock tires and my speedo would be off by 8%

im just looking for input and feedback, any insights on when some sort of tuner will be available to do things like correct the speedo, take the stupid rev limit off in neautral/park and take the govermor off in 1st and 2nd gear??? anyone think the 4.88's will be too low?

at 80mph i would be spinning 2835 rpm, will that kill my fuel mileage? right now im spinning 2524 at 80 mph?

im thinking i will like the lower gears because i do tow and haul quite often

 

I will limit my comments on the gearing...because so much of that is a personal preference. I would not decide which gears to go with based on your speedo issue. Keep them separate...IMHO.

Now...for your speedo issue. Here is the best kept secret...it's called TruSpeed Speed Sensor Recalibrator from Superlift. A wonderful product...and simple install. Here is the link: http://www.superlift.com/accessories/truspeed.asp

Hope that helps some...and good luck!

biz

_____________________________
2003 F250 SD SC 142" XLT FX4 V10 Auto 4x4 3.73s

 

Go 4.88. There are plenty of boys who wish they had a bigger number on their SD gearing, but I have read or heard of no one who wishes they had smaller gear ratio in their V-10 powered SD's.

Where you are plowing, towing, and running oversize rubber, go 4.88.

I might add, if you are even thinking of fuel mileage while driving one of these 6-7000# bohemouths 80 MPH down the highway, you are in la la land regardless of the rear gear ratio. BTW, what state or fed highway is legal to run 80 MPH?

 

yhose tires will need a set of 88's as to the speedo a sct tuner can help that by reprograming the rear axle ratio and tire size. check out thier web to see what i mean.

 

sweet, ill throw the 4.88's in there.. just wanted some imput from other folks....no im not worried about mpg with this truck...mos tof my gas is payed for by work....but i still liek to try and make the best mpgs i can

charlie....you still liking your 4.56's??

get that exhaust installed yet?

how much does the sct tuner run?

 

well nm, i ordered the sct tuner....cant wait to play with it

 

I'm thinking of going 4.88's with stock tires. Call me weird.

I have 3.73's now. That's a 30% increase in torque to the ground.

30% ?!?!?!?!!? I'd need a 540 cube engine to put that sort of torque to the ground.

 

i love a low geared truck....go for it!

 

Something to remember, your ring and pinion has nothing to do with speedometer reading on these trucks. The speedo is reading from the ring gear, which completes one rotation every time the tires do. It does not matter if you have 3.23 or 5.13 gearing, the ring gear completes one rotation each time the tires do. What the gears change is the speed of the pinion rotation, which in turn affects your RPM. So a factory speedo with 35's and 3.73 gearing will read the same as a factory speedo with 35's and 4.88 gearing, only at a higher RPM. The tires are the only factor that will manipulate the speedometer.

 

haha, im an idiot becaus ei knew that, but forgot!!!

thanks for the heads up

hopefully my xcalibrator 2 from sct will take care of all that

im looking foward to the 7k mile wakeup yall are tlaking about

 

i love it with the 4:56's and no it's to darn hot to work on the truck to install the new system. 98 today up to a possible 105 tomorrw and wed.
with that much heat even sex can wait till it cools off.

 

4wd asked "BTW, what state or fed highway is legal to run 80 MPH?"

one legitimate answer ( not sure of Nevada or Montana any more)

Texas Inter State Ten (I-10) from just west of San Antonio out about 680+ miles to El Paso is now 80 MPH on the signs...... except in the zones going through small towns like Ozona, Fort Stockton, Sierra Blanco etc.

I have not done the trek from Fort Hood to Tucson since they put up the new signs... but earlier this year when the signs said 75mph I was keeping pace with the State Patrol at 84MPH (grin)

And don't none of you do gooder 55mpg, ecology minded, pinko tree hugger, safety ***** give me any crap... I will choose high speed and short travel time over safe and sane, pedestrian, mind numbing, hours and hours of nothingness,..... any day

For what it is worth.... I don't get any worse MPG form 84mph then 75mph

and there is extra credit for any one who can calculate travel time on a 1435 mile one way trip at 75mph vs. 85mph (yea, yea, I know you can't sustain and average 75 or 85 with on ramp and off ramp time, gas and piddle breaks) but just do the math anyway and see how different the travel time is and think about it a little......

 

2.2 hrs difference between driving 75 MPH vs 85 mph on an entire 1435 mile trip. 3 hours difference in time between driving that trip averaging 65 vs 75 MPH. And 4 hours difference on a more realistic 55 mph avg speed vs 65 mph avg speed on that 1435 mi trip.

What's the point?
2 hours that big a deal in anyone's life? 3 hrs? How about 4 hrs?

I think hurling down the highway at 80 MPH with one of these 6000-7000# SD is beyond anything safe. I guess I am not so concerned for the safety of the individual who is driving that speed as I am for the innocent civilians that must share the highway with him while he is on his mission.

 

maybe i should throw 7.17's in it so i can hardly run 80

id be turning 4400 at 80

 

Two questions:
1. Have you installed the tires yet?
2. How much of a difference is there in ride quality empty with the plow springs?