Gear Ratio
Thread Starter
|
Senior User
Joined: Sep 2006
Posts: 106
Likes: 0
Gear Ratio
Gang,
Looking for some advice from those who did and any experts in the field. I want to find the right gear to bring me effectively back to a stock setup on my truck. Right now the truck has a 6" 4 Link lift, 37" Toyo's on 20" rims with the stock set of 3.73 gears. I pull a boat and a 28ft Toy hauler occasionaly. I have spoke to 3 shops and I am getting all kinds of recommendations and nothing consistent. I have had 4.10's all the way to 4.89's. The truck has no mods on it outside those mentioned. My goal is to get the truck back to where she was designed to be best all around. Based on my calc's a 4.10 will yield me an effective ratio of 3.66 @ the rear with the tires I have or a 4.30 will give me a 4.84 effectively. What would you guys take? New Territory for me!
Thanks,
Pit
Looking for some advice from those who did and any experts in the field. I want to find the right gear to bring me effectively back to a stock setup on my truck. Right now the truck has a 6" 4 Link lift, 37" Toyo's on 20" rims with the stock set of 3.73 gears. I pull a boat and a 28ft Toy hauler occasionaly. I have spoke to 3 shops and I am getting all kinds of recommendations and nothing consistent. I have had 4.10's all the way to 4.89's. The truck has no mods on it outside those mentioned. My goal is to get the truck back to where she was designed to be best all around. Based on my calc's a 4.10 will yield me an effective ratio of 3.66 @ the rear with the tires I have or a 4.30 will give me a 4.84 effectively. What would you guys take? New Territory for me!
Thanks,
Pit
Postmaster
Joined: Jan 2005
Posts: 4,424
Likes: 12
From: BC Canada
I would go 4.30's. Go to 4Low.com there is a gear ratio calculator. Insert you existing wheel and tire curcumference and get your effective gear ration, then calculate with the new ratio what you will end up as. Using 34 inches diameter stock 3.73, going to 37 yields that a 4.06 or 4.10 would keep you at the same ratio. Given you are pulling hard and you have a high lift, I would go 4.30. Do you have your driveline shimmed properly for the lift? Becasue this could really cause some issues with u-joint life over time.
4Lo.com :: Tire Size Change, New Gear Ratio Calculator
4Lo.com :: Tire Size Change, New Gear Ratio Calculator
Hotshot
Joined: Aug 2006
Posts: 17,400
Likes: 319
From: Whittier, CA
No need to jump ship. You can get that calculator right here at our beloved FTE:
Automotive Calculators offer to you by Ford Trucks Enthusiasts | www.ford-trucks.com
Automotive Calculators offer to you by Ford Trucks Enthusiasts | www.ford-trucks.com
Lead Driver
Joined: Jun 2007
Posts: 6,757
Likes: 5
From: Corvallis, OR
yeah, 4.30s will bring you back to the stock end ratio. I am going with 4.30s with my 35s which will put me 5% lower than stock. If you tow often I would advise 4.56s which will be about the same as 4.10s with stock tires. This will help with low end when towing and also compensate for the increased rolling mass of the larger tires/wheels.
Post Fiend
Joined: Jul 2005
Posts: 14,582
Likes: 12
From: 21791
4.30's wont quite get you back to stock, they will get you to a 3.66. Go with a 4.56, it will bring you to a 3.88, which is a little bit deeper than stock, but you need that considering how much heavier the wheel/tire combo is, to get going. It will be better for towing as well. Cartman, i think your calculator is broke.
Thread Starter
|
Senior User
Joined: Sep 2006
Posts: 106
Likes: 0
Sounds like the 4.30s are my mid range if that make sense. I think 4.10 is to shallow....4.56's though I am still considering. I just don't want to take away from it for daily driving as in CA its average 75mph.
As for the drive line being shimmed, yes it is, the dealer did and I had them recheck the angles and all is good.
Pit
As for the drive line being shimmed, yes it is, the dealer did and I had them recheck the angles and all is good.
Pit
Lead Driver
Joined: Jun 2007
Posts: 6,757
Likes: 5
From: Corvallis, OR
4.30's wont quite get you back to stock, they will get you to a 3.66. Go with a 4.56, it will bring you to a 3.88, which is a little bit deeper than stock, but you need that considering how much heavier the wheel/tire combo is, to get going. It will be better for towing as well. Cartman, i think your calculator is broke.
Trending Topics
Logistics Pro
Joined: May 2004
Posts: 3,616
Likes: 882
I have the same tire size, same lift heigth but 17" wheels. I run 4.56's and think it pulls great!
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
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
Thread Starter
|
Senior User
Joined: Sep 2006
Posts: 106
Likes: 0
Oh here I am going to save you all the headache!!!!
I gave an invalid dimension...My tires are a 325/60/20 which is a 35" (35.4 to be exact) not 37"!!!!!
So with that in mind a set of 4.30's will yield me a 3.84 or 4.10's a 3.66 right? My only concern is driving the RPMS off the map with 4.30's or am I worrying about nothing? Gotta figure Cali runs 75mph avg traffic speed.
BTW I'm sorry I missed that on the get go!!!!!!!
Pit
I gave an invalid dimension...My tires are a 325/60/20 which is a 35" (35.4 to be exact) not 37"!!!!!So with that in mind a set of 4.30's will yield me a 3.84 or 4.10's a 3.66 right? My only concern is driving the RPMS off the map with 4.30's or am I worrying about nothing? Gotta figure Cali runs 75mph avg traffic speed.
BTW I'm sorry I missed that on the get go!!!!!!!
Pit
Lead Driver
Joined: Jun 2007
Posts: 6,757
Likes: 5
From: Corvallis, OR
I have 315/75/16s which are 34.5" tall. I calculated with 4.30s I'll be turning 2016 rpms at 65 mph. With your tires at 75mph you would be turning about 2267 rpms. Thats pretty high for cruising, 4.10s may be all you want to go.
Now, I bought my gears before buying my SCT tuner. With the tuner, I think I could get away with not changing gears as the power is far beyond what it was stock. Something to think about, spend $400-500 on a tuner or $1000-$2000 on gears.
Now, I bought my gears before buying my SCT tuner. With the tuner, I think I could get away with not changing gears as the power is far beyond what it was stock. Something to think about, spend $400-500 on a tuner or $1000-$2000 on gears.
Tuned
Joined: Nov 2005
Posts: 267
Likes: 5
I have 315/75/16s which are 34.5" tall. I calculated with 4.30s I'll be turning 2016 rpms at 65 mph. With your tires at 75mph you would be turning about 2267 rpms. Thats pretty high for cruising, 4.10s may be all you want to go.
Now, I bought my gears before buying my SCT tuner. With the tuner, I think I could get away with not changing gears as the power is far beyond what it was stock. Something to think about, spend $400-500 on a tuner or $1000-$2000 on gears.
Now, I bought my gears before buying my SCT tuner. With the tuner, I think I could get away with not changing gears as the power is far beyond what it was stock. Something to think about, spend $400-500 on a tuner or $1000-$2000 on gears.
Like you say, the gears are 2000, the tuner is 500. However, you will won't have any engine problems associated with tuners if you do the gears. I plan on throwing in a posi unit in the front diff when I do mine as well.
Junior User
Joined: Oct 2007
Posts: 96
Likes: 0
Go 4.56 like has been said. You won't be sorry. You'll be geared a tad lower than stock to make up for the heavy rubber. A buddy of mine has this combo and it works great towing or not. Your EGTs will go down and your mileage up.
Tuned
Joined: Nov 2005
Posts: 267
Likes: 5
I thought bigger tires and bigger gears reduced fuel economy.