Gears and Lockers
Fleet Mechanic
Joined: Oct 2012
Posts: 1,943
Likes: 21
I did a full axle swap in mine to move from 3.73 to 4.30 and at the time I had 285 70 17 tires and it drove like a completely different vehicle. So much so that I almost didn't make the jump up to 315 70 17. But I did. With the taller tires it negated most of the gains from the gears but it bumped it up to an effective ratio of around 3.90 which is still better than 3.73 but not by much. With stock size tires and 4.30 from my experience there would not be a need to go deeper than that.
Moderator
Joined: Jul 2010
Posts: 12,055
Likes: 1,559
From: Media PA
I did a full axle swap in mine to move from 3.73 to 4.30 and at the time I had 285 70 17 tires and it drove like a completely different vehicle. So much so that I almost didn't make the jump up to 315 70 17. But I did. With the taller tires it negated most of the gains from the gears but it bumped it up to an effective ratio of around 3.90 which is still better than 3.73 but not by much. With stock size tires and 4.30 from my experience there would not be a need to go deeper than that.
Thread Starter
|
Laughing Gas
Joined: May 2011
Posts: 855
Likes: 40
From: SoCal
I thought about possibly finding some stock 4.30 axles from an Excursion and just doing a full axle swap. I might still go that route if the right deal comes up when it is time for the project.
We plan on keeping the stock tire size and ride height, but will be spending quite a bit of time with my 9000lb camper in tow. Plan on heading out west and into the mountains etc. Thought with the weight, elevation and grades the steeper 4.56 gears would be the way to go.
We plan on keeping the stock tire size and ride height, but will be spending quite a bit of time with my 9000lb camper in tow. Plan on heading out west and into the mountains etc. Thought with the weight, elevation and grades the steeper 4.56 gears would be the way to go.
Fleet Mechanic
Joined: Mar 2019
Posts: 1,293
Likes: 164
I paid $650 I believe for the set from a salvage yard. It took me almost 6 months of searching. I wanted a set from an excursion so that I wouldn't have to mess with changing pinion yokes as the pickups sometimes used a different yoke.
Laughing Gas
Joined: Jan 2020
Posts: 831
Likes: 171
From: Greenville, TX
ARB front and back?! Niiiiiiiiice.
While It seems like you've got your mind set, depending on your usage, you may want to consider going a hair steeper (provided it's not too late). @WE3ZS tried talking me into 5.13s, but my job at the time called for 100+ miles on the interstate daily. At that point, I wished I'd gone with the 4.56. Now that I work 6.5 miles from the house and am mudding often, and I wish I'd gotten the 5.13s. My Ex's usage has changed quite a bit. I opted for 4.88, and after a year of driving that ratio, it's a great middle ground to be in with 37s. Plus, it will match up more or less with what you expect from factory tires and 4.30 (aside from the extra rotational mass and unspring weight). All that said, 4.56 will still feel much better than the factory 3.73s! I can't wait to see how your build goes!
@jayro88 take a look at www.car-part.com. I've used it to search salvage lots around me for all sorts of stuff.
While It seems like you've got your mind set, depending on your usage, you may want to consider going a hair steeper (provided it's not too late). @WE3ZS tried talking me into 5.13s, but my job at the time called for 100+ miles on the interstate daily. At that point, I wished I'd gone with the 4.56. Now that I work 6.5 miles from the house and am mudding often, and I wish I'd gotten the 5.13s. My Ex's usage has changed quite a bit. I opted for 4.88, and after a year of driving that ratio, it's a great middle ground to be in with 37s. Plus, it will match up more or less with what you expect from factory tires and 4.30 (aside from the extra rotational mass and unspring weight). All that said, 4.56 will still feel much better than the factory 3.73s! I can't wait to see how your build goes!
@jayro88 take a look at www.car-part.com. I've used it to search salvage lots around me for all sorts of stuff.
Thread Starter
|
Laughing Gas
Joined: May 2011
Posts: 855
Likes: 40
From: SoCal
My build will have ARB lockers front and rear with chromoly axles. BTW the axles in the Ex now have no leaks, no rust, and no noises. A little emery cloth and some Rustoleum and they will look like new. Any body interested in them can PM me.
Thread Starter
|
Laughing Gas
Joined: May 2011
Posts: 855
Likes: 40
From: SoCal
ARB front and back?! Niiiiiiiiice.
While It seems like you've got your mind set, depending on your usage, you may want to consider going a hair steeper (provided it's not too late). @WE3ZS tried talking me into 5.13s, but my job at the time called for 100+ miles on the interstate daily. At that point, I wished I'd gone with the 4.56. Now that I work 6.5 miles from the house and am mudding often, and I wish I'd gotten the 5.13s. My Ex's usage has changed quite a bit. I opted for 4.88, and after a year of driving that ratio, it's a great middle ground to be in with 37s. Plus, it will match up more or less with what you expect from factory tires and 4.30 (aside from the extra rotational mass and unspring weight). All that said, 4.56 will still feel much better than the factory 3.73s! I can't wait to see how your build goes!
@jayro88 take a look at www.car-part.com. I've used it to search salvage lots around me for all sorts of stuff.
While It seems like you've got your mind set, depending on your usage, you may want to consider going a hair steeper (provided it's not too late). @WE3ZS tried talking me into 5.13s, but my job at the time called for 100+ miles on the interstate daily. At that point, I wished I'd gone with the 4.56. Now that I work 6.5 miles from the house and am mudding often, and I wish I'd gotten the 5.13s. My Ex's usage has changed quite a bit. I opted for 4.88, and after a year of driving that ratio, it's a great middle ground to be in with 37s. Plus, it will match up more or less with what you expect from factory tires and 4.30 (aside from the extra rotational mass and unspring weight). All that said, 4.56 will still feel much better than the factory 3.73s! I can't wait to see how your build goes!
@jayro88 take a look at www.car-part.com. I've used it to search salvage lots around me for all sorts of stuff.
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
Laughing Gas
Joined: Jan 2020
Posts: 831
Likes: 171
From: Greenville, TX
Thread Starter
|
Laughing Gas
Joined: May 2011
Posts: 855
Likes: 40
From: SoCal
When all 10 cylinders are behaving on mine, it's got a respectable pull. Again, it all comes down to your usage and making an informed decision based on that. I don't know how many commenters I've seen in the course of the last year and a half that I've been here, that say "get X.XX, because if you get X.XX (the very next ratio below) it will suck and won't work and blah blah blah. Our trucks don't magically suck ***** at 4.30 and come ferociously alive when changed to 4.56, or likewise with 4.56 vs 4.88. Is there a difference though? Sure. Will you be happy with a 4.56? Absolutely. If you think you might go bigger in the future, or if this is an offroad toy (or will be eventually, like mine), then I'd recommend the shorter gear.
Did you stay leaf sprung, or did you go with a coil swap?
Did you stay leaf sprung, or did you go with a coil swap?
Logistics Pro
Joined: May 2017
Posts: 3,523
Likes: 483
From: Southern OH
A Dana 70 is a downgrade from a Ford 10.5, 2nd gen Cummins auto trucks use Dana 70s and they break axle shafts regularly when turned up, some people even carry around a spare with them, the Ford 10.5 is about 10 times more common than the Dana 70 and I have never seen someone break and axle shaft in one unless it was a high hp sled pulling truck. Dana 70s are also harder to work on, parts are more expensive, and harder to find since they aren't as common. Also to the OP if you have a gas Excursion 5.13 gears would be better with 37s.
Lead Driver
Joined: Apr 2011
Posts: 8,259
Likes: 346
From: Northern California
I can say the same for the sterling 10.5 shafts, guys in toyotas and jeep rockcrawlers break stock sterling 20.5 shafts all the time.
at the end of the day both the dana 70 and sterling 10.5 both use a 35 spline 1.50” diameter 1054 carbon steel shaft. Strong to be sure but hardly up to the abuse determined users can dish out.
The answer to breaking stock shafts is better material and larger size, 40 spline 1.70” 300m comes to mind
( i have only broken 1 of those and It wasnt an easy feat )
at the end of the day both the dana 70 and sterling 10.5 both use a 35 spline 1.50” diameter 1054 carbon steel shaft. Strong to be sure but hardly up to the abuse determined users can dish out.
The answer to breaking stock shafts is better material and larger size, 40 spline 1.70” 300m comes to mind
( i have only broken 1 of those and It wasnt an easy feat )
Thread Starter
|
Laughing Gas
Joined: May 2011
Posts: 855
Likes: 40
From: SoCal
OK time for an update on this project. Sad news the gentleman at Custom Axle Design in Mississippi who was personally handling my axle mods passed away. His wife has decided to close the business. He was a good guy, I'm very sorry at his passing. My prayers to his family. He got sick right after taking on my project. So, here's my path forward. In the rear I will be keeping the Sterling 10.5 and adding an OX Locker with 4:56 gears. In the front I will upgrade the D50 to a D60 with OX Locker and 4:56 gears. I'm running 35s on 17 wheels and 4:30 gears right now and the Ex seems to be very comfortable with this set up. The 4:56 gears should sweeten it a little. I'm still looking to do a turnkey operation with remanufactured axles and installing lockers and gears in them. My goal is to get this done by spring. Covid has taken a toll on a lot of shops. Parts and labor are in short supply. As always, I appreciate any thoughts and advice from the FTE family.