Hey i was wondering if i get like 37s or 38s and i have stock gears can i get away with just getting a programmer and changing the shift points and what not? i really dont wanna spend the money on new gears, any input would be nice. I'd also just be doing driving like around town and rarely the highway. thanks

 

Hi.

1. It's gonna be a dog.
2. The mileage will tank.
3. Braking distances will be longer.
4. It's going to stress the tranny and other drivetrain components.
5. Do both, imho.

MGD

 

ok thanks but could i get away with just the programmer for a while?

 

Sure you can get away with it for awhile.......depending on how long you define "awhile"

Assuming you have factory 3:73's those 38's are going to stress your motor, transmission, transfer case, that's just for starters.

I've read, re-read and read again just about every post in the Tuner Section and have decided to wait until I can get it, my 4:56 or 4:88 gears and 36's all at the same time.

Don't go cheap when it comes to modding your truck. If you're looking at spending $2k on tires, what's another grand for gears to make the tires work with your truck instead of against it?

 

If you are going to mod your truck, do it right, don't do a halfass job. 37's or 38's require a lift, gears, and a tune.

 

Yeah thats a big tire. If you don't regear it'll be a dog bad and alot of stress. Go with atleast a 4.56 gear too.

 

Getting the big picture yet?
Gears....at least 4.56 preferably 4.88....
Lift....6" at the least....
Programmer.....it will tie in everything....preferably with custom tunes....

 

ah alright thanks guys i understand all that

 

And Ray, MGD brought up a factor that is generally overlooked. Your braking distances will be longer and nothing you can do, outside of a redesigned, bigger brake disk and pad setup is going to change that. So, don't "tailgate" anyone.

- Jack

 

Doesnt it also depend on what year truck you have??

2009-2010 trucks second gear is almost the same ratio as pre 2009 trucks first gears. For a pre 2009 truck to have an equivelent 1st gear ration of a 2009-2010 1st gear they would have to regear to almost a 5.20 or something in that range. Thats the benefit of having the 6 speed transmission. The 2009 raptor which comes stock with 35's only runs a 4.10 from Ford, and you can beat the snot out of a Raptor.

37-38's would be pushing the envelope though especially if you start off- roading it, and putting more strain on it, then just driving on the streets, but i agree, there are other things that are going to be effected such as breaking, and gas mileage

**edit**
ok...i found the math..tbear853 originally posted this

"The 4R70W, 4R75W, 4R70E, 4R75E, AODE all had a 2.84 first gear,
2.84 X 3.55 rear = 10.08 overall ratio
2.84 X 3.73 rear = 10.59 overall ratio
2.84 X 4.10 rear = 11.64 overall ratio
2.84 X 4.56 rear = 12.95 overall ratio

The 4R100 had a 2.71 first gear,
2.71 X 3.55 rear = 9.62 overall ratio
2.71 X 3.73 rear = 10.11 overall ratio
2.71 X 4.10 rear = 11.11 overall ratio
2.71 X 4.56 rear = 12.35 overall ratio

The new 6 speed 6R80E has a 4.17 first gear ... and a 2.34 second gear
4.17 X 3.55 rear = 14.80 overall ratio
4.17 X 3.73 rear = 15.55 overall ratio
4.17 X 4.10 rear = 17.10 overall ratio

2.34 X 3.55 rear = 8.30 overall ratio in second gear

The new 2010 Ford Truck 6R80E 6 speed transmission with it's low geared 4.17 first gear and a 3.55 geared axle is a lower overall ratio than either of the pre 2010 4 speed automatics in the F-150 even if you were to re-gear those pre 2010 trucks with a 4.56 rear axle (and front axle) gear.

Hell, second gear in this transmission is not all that far from first in the 4 speeds!

Another way to look at it is 6R80E's first gear 4.17 X 3.55 rear = 14.80 overall ratio devided by 2.84 first gear of the majority of the 4 speeds = a 5.21 rear gear that would be needed with a 4R70W, 4R75W, 4R70E, 4R75E, AODE ... to match the 6R80E in first gear pulling.

The 4R100 with it's 2.71 first gear needs a 5.46 rear gear to match it. ""

 

thanks jack and Timelessr1

 

Re gear is the best mod I've done to my truck.

but then again. Once you re gear and get bigger tires you kinda have to get a tuner to reprogram the speedo.

 

New gears. But that ultimately leads to a programmer. So do both and be happy.

 

That's a really good thing to know!

But if you're like me I find my truck in top gear a lot more than first if you'd want to average that out....

 

The truck will be unpleasant to drive with 37" or 38" tires and stock gears with or without a tuner. It will still shift in and out of overdrive on the slightest hill (maybe even in the flats depending on the speed). It will put a lot of strain on the transmission and torque converter when starting (and due to hunting for gears). I wouldn't do it.