Gearing
Thread Starter
|
Senior User
Joined: Jan 2010
Posts: 136
Likes: 0
Gearing
While I have my front axle apart, I'm thinking I should to a complete rebuild, change gearing and add an ARB Air locker.
I was watching a video on gearing today. Using their formula, new tire size (37") times current gears (3.55) = 13.35 divided by old tire size (32") = 4.10.
Does this sound right? I am going from stock tires 235's to 37's. I have a few modest mods planned to get me to 400 HP and 600 foot pounds of torque.
I was watching a video on gearing today. Using their formula, new tire size (37") times current gears (3.55) = 13.35 divided by old tire size (32") = 4.10.
Does this sound right? I am going from stock tires 235's to 37's. I have a few modest mods planned to get me to 400 HP and 600 foot pounds of torque.
Thread Starter
|
Senior User
Joined: Jan 2010
Posts: 136
Likes: 0
I want to maintain what I have. It has reasonable fuel mileage, power and tows well.
Hotshot
Joined: Dec 2005
Posts: 14,377
Likes: 609
From: evansville in
If you aren't towing real heavy the 4.10 will get you then but more gear may be better really.
I know my 3.55s and 285 don't get 10k + moving from a stop great without torturing the converter..
I know my 3.55s and 285 don't get 10k + moving from a stop great without torturing the converter..
Cargo Master
Joined: Nov 2010
Posts: 2,797
Likes: 10
While I have my front axle apart, I'm thinking I should to a complete rebuild, change gearing and add an ARB Air locker.
I was watching a video on gearing today. Using their formula, new tire size (37") times current gears (3.55) = 13.35 divided by old tire size (32") = 4.10.
Does this sound right? I am going from stock tires 235's to 37's. I have a few modest mods planned to get me to 400 HP and 600 foot pounds of torque.
I was watching a video on gearing today. Using their formula, new tire size (37") times current gears (3.55) = 13.35 divided by old tire size (32") = 4.10.
Does this sound right? I am going from stock tires 235's to 37's. I have a few modest mods planned to get me to 400 HP and 600 foot pounds of torque.
The 2000 and up axles actually came with a 4.30 option. If I were you running 37s and towing i would not go with anything longer than a 4.30 ratio. A lot of trucks we have built have said this is nearly perfect. Some have gone as high as 4.56s. I can tell you personally that if I were to tow with 37s and 4.10s it would not be the best experience.... 37s on 3.55s... yeah forget it, unless you are hauling around a light camper trailer without the need for overdrive...
Also if you have a 400ho motor your more than likely up in the 900 ft/lbs of torque. You will fine out it will be very hard to keep a 7.3 cool yanking a trailer around at a 400hp setting with 37s under it. We just finished a build doing just that and it was not cheap!
Senior User
Joined: Dec 2014
Posts: 348
Likes: 0
For final drive ratio comparisons on your tranny if you actually math out a 3.55 or a use a 3.73 base ratio you come to a 4.36s.
The 2000 and up axles actually came with a 4.30 option. If I were you running 37s and towing i would not go with anything longer than a 4.30 ratio. A lot of trucks we have built have said this is nearly perfect. Some have gone as high as 4.56s. I can tell you personally that if I were to tow with 37s and 4.10s it would not be the best experience.... 37s on 3.55s... yeah forget it, unless you are hauling around a light camper trailer without the need for overdrive...
Also if you have a 400ho motor your more than likely up in the 900 ft/lbs of torque. You will fine out it will be very hard to keep a 7.3 cool yanking a trailer around at a 400hp setting with 37s under it. We just finished a build doing just that and it was not cheap!
The 2000 and up axles actually came with a 4.30 option. If I were you running 37s and towing i would not go with anything longer than a 4.30 ratio. A lot of trucks we have built have said this is nearly perfect. Some have gone as high as 4.56s. I can tell you personally that if I were to tow with 37s and 4.10s it would not be the best experience.... 37s on 3.55s... yeah forget it, unless you are hauling around a light camper trailer without the need for overdrive...
Also if you have a 400ho motor your more than likely up in the 900 ft/lbs of torque. You will fine out it will be very hard to keep a 7.3 cool yanking a trailer around at a 400hp setting with 37s under it. We just finished a build doing just that and it was not cheap!
Trending Topics
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
If you do the math with 325/80/16 on 3.55 then
Effective gear ratio would be 2.91
New gear needed comes to 4.33
Effective gear ratio would be 2.91
New gear needed comes to 4.33
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Cargo Master
Joined: Nov 2010
Posts: 2,797
Likes: 10
Well I'd get a set of 4.30s if I were you and call it a day...
Senior User
Joined: Dec 2014
Posts: 348
Likes: 0
My f150 is 4wd can't get 4.30 for the front last I checked it's got 4.56's in it for a couple years now no complaints with that gear setup
Edit: now I realize you were probably talking to the op lol
Edit: now I realize you were probably talking to the op lol
Thread
Thread Starter
Forum
Replies
Last Post
racsan
Brakes, Steering, Suspension, Tires, & Wheels
4
Oct 3, 2007 11:05 AM
96fourbanger
Clutch, Transmission, Differential, Axle & Transfer Case
1
Nov 24, 2004 05:12 PM