montypower
Adventure Time!
Appreciate the kind words.
Bummed you didn't get more adventures with your rig! You put some serious work into it... Major cool factor too!
Expedition Ready! 2020 F250 on 37s, Locked F/R, 4.30 Gears, HP D60, PSC Hydro, FOX 2.5" + Camper - 875W Solar - Lithium - 40g H2o! $98k - Arizona
- Thread starter montypower
- Start date
Appreciate the kind words.
Bummed you didn't get more adventures with your rig! You put some serious work into it... Major cool factor too!
wadingthroughlife
Member
Sent DM; can call too! Debating need for the camper, having a trailer, but we do like it too for versatility.
montypower
Adventure Time!
Let's talk gear / axle ratios!
Most of the F250/F350 Super Duty trucks with gasoline motors have a factory 3.73 axle ratio. While some of the 7.3L godzilla equipped models have 3.55 axle ratio. 4.30 axle ratio is "optional" for all models.
What is happening?
Your engine rotational force is sent into the transmission, through the transfer case (if 4wd) and into the axle(s) via the driveshaft. The axle ratio increases engine revolutions for every 1 tire revolution essentially multiplying / increasing engine torque.
How is this calculated?
If your driveshaft completes 3.73 complete revolutions while the tire completes 1 full rotation... you have a 3.73 axle ratio.
However, if you rotate your driveshaft 4.3 complete revolutions for the tire to complete 1 full rotation... you have 4.30 axle ratio.
How to express gear ratios?
3.73 is a "higher" gear ratio than 4.30 which is "lower"
This vocabulary may seem inversed but you have to think about what the gears are doing. The larger the ratio number the slower the tire turns at the same driveshaft speed. Think LOW and SLOW. You may also think "4WD LOW" is for going slow.
Who cares?
It changes engine torque. Ford increases maximum weight moving ability (GCWR) from 2,500 to 6,500 depending model and axle ratio!
Are "lower" gears better? Should I install the "lowest" gears possible?
It depends. For towing/hauling lower gears will increase engine torque. However, they increase torque by increasing engine revolutions to travel the same distance. More engine revolutions = increased energy / fuel consumption. There's a balance to be had.
How does increasing tire size affect the gear ratio?
Larger than stock tires effectively make your axle ratio "higher". For instance, a 32.1" diameter tire has a circumference of 100"; meaning if you rotated the tire 1 revolution it would travel 100" in distance. However, a 37" diameter tire has a circumference of 115" meaning 1 tire rotation = 115" distance.
Real life application Stock Super Duty Tire Size:
275/65R18 = 32.1" Diameter
Oversized Tires:
37x12.5R17 = 36.5" Diameter
Percentage difference (36.5 / 32.1 = 1.137) of 13.7% increase in tire diameter.
Which means if your truck had 3.73 gears and you didn't "re-gear" your "effective" ratio with the larger tires would be 3.28 (13.7% higher). That's significant! It will reduce engine torque and towing ability.
To maintain the factory 3.73 axle ratio with 37" tires... you'd need to "lower" your gear ratio by 13.7%. Which would yield 4.24 gear ratio. The closest factory ratio is 4.30 axle ratio (slightly lower).
SOOOOO..... Maintaining the near perfect factory gear ratio with 37" tires you want the optional 4.30 axle gears.
Which is why we ordered the truck with factory 4.30 gears! Our speedometer is dead on. Transmission functions as if it had factory 32.1" tires.
Now... you could install lower 4.88 gears to achieve the maximum factory specification numbers with the 37" tires. But it's not necessary. Biggest issue to avoid is installing oversized tires without correcting the gear ratio. Cost of larger tires should also include proper axle gearing (as needed).
Most of the F250/F350 Super Duty trucks with gasoline motors have a factory 3.73 axle ratio. While some of the 7.3L godzilla equipped models have 3.55 axle ratio. 4.30 axle ratio is "optional" for all models.
What is happening?
Your engine rotational force is sent into the transmission, through the transfer case (if 4wd) and into the axle(s) via the driveshaft. The axle ratio increases engine revolutions for every 1 tire revolution essentially multiplying / increasing engine torque.
How is this calculated?
If your driveshaft completes 3.73 complete revolutions while the tire completes 1 full rotation... you have a 3.73 axle ratio.
However, if you rotate your driveshaft 4.3 complete revolutions for the tire to complete 1 full rotation... you have 4.30 axle ratio.
How to express gear ratios?
3.73 is a "higher" gear ratio than 4.30 which is "lower"
This vocabulary may seem inversed but you have to think about what the gears are doing. The larger the ratio number the slower the tire turns at the same driveshaft speed. Think LOW and SLOW. You may also think "4WD LOW" is for going slow.
Who cares?
It changes engine torque. Ford increases maximum weight moving ability (GCWR) from 2,500 to 6,500 depending model and axle ratio!
Are "lower" gears better? Should I install the "lowest" gears possible?
It depends. For towing/hauling lower gears will increase engine torque. However, they increase torque by increasing engine revolutions to travel the same distance. More engine revolutions = increased energy / fuel consumption. There's a balance to be had.
How does increasing tire size affect the gear ratio?
Larger than stock tires effectively make your axle ratio "higher". For instance, a 32.1" diameter tire has a circumference of 100"; meaning if you rotated the tire 1 revolution it would travel 100" in distance. However, a 37" diameter tire has a circumference of 115" meaning 1 tire rotation = 115" distance.
Real life application Stock Super Duty Tire Size:
275/65R18 = 32.1" Diameter
Oversized Tires:
37x12.5R17 = 36.5" Diameter
Percentage difference (36.5 / 32.1 = 1.137) of 13.7% increase in tire diameter.
Which means if your truck had 3.73 gears and you didn't "re-gear" your "effective" ratio with the larger tires would be 3.28 (13.7% higher). That's significant! It will reduce engine torque and towing ability.
To maintain the factory 3.73 axle ratio with 37" tires... you'd need to "lower" your gear ratio by 13.7%. Which would yield 4.24 gear ratio. The closest factory ratio is 4.30 axle ratio (slightly lower).
SOOOOO..... Maintaining the near perfect factory gear ratio with 37" tires you want the optional 4.30 axle gears.
Which is why we ordered the truck with factory 4.30 gears! Our speedometer is dead on. Transmission functions as if it had factory 32.1" tires.
Now... you could install lower 4.88 gears to achieve the maximum factory specification numbers with the 37" tires. But it's not necessary. Biggest issue to avoid is installing oversized tires without correcting the gear ratio. Cost of larger tires should also include proper axle gearing (as needed).
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montypower
Adventure Time!
How can the Truck Camper work with kids (more than 2 people)?
1. Truck Seating: Flexible
Truck can seat up to 6 people! It has a proper front bench seat (seats 3).
The front easily converts between the console and seat by flipping up/down.
The rear split fold 60/40 bench seats 3. Lots of combinations could be used here!
The rear seat is 2 separate parts. Meaning you could have 1 rear seat (60% driver side removed) or 2 rear seats (40% passenger side removed).
2. Camper Seating:
It will fit 3-4 people. Plus an additional small child may fit on the short bench side. We've also had guests sit on the bathroom floor (which is elevated and works well).
3. Camper Sleeping:
It is really a 2 person (queen bed) configuration. However, a small child would fit on the dinette seat (long side).
4. Additional Sleeping Options:
Truck Sleeping Platform! There are some configuration options here...
A) Sleep on the bench seat Front or Rear. Simple, Quick setup. It would be possible to sleep up to 2 (1 front / 1 rear).
B) Rear seat delete options. Could be entire or partial. The 60% driver side or 40% passenger side seat can be removed individually.
GooseGear has some good photos showing what it looks like in either configuration:
www.goose-gear.com
I would look to build a custom platform to maximize storage and allow for quick setup. Ideally... remove the 60% driver side (2 seats). Build a fixed platform in this area. To maximize space, platform height could match the front center console height (approx. 20" from the floor). Giving a ton of secure storage under the platform. On top of the platform foam cushions and sleeping gear could be stored.
The 20% passenger seat can fold both up (seat bottom) and down (seat back). Folding the seat back down gives the most width and matching height to the center console (ideal).
This gives around 28" of headroom above the platform which is plenty to move around.
Total width side/side is 67" which can work for many adults.
Total width (from back wall to center console) is 30" or more. With the seats forward it adds another 6" or more.
The platform could have a hinged section that would extend over the 40% passenger seat giving a flat sleeping area.
Alternatively, the entire back seat could be removed with a bike platform installed (as we used the truck). Bikes could be store outside at night; and the platform could be used for sleeping on. Then the front bench seat could be utilized for transporting the additional passenger.
Interior sleeping configurations are versatile and by far the most secure and poor weather friendly. Plus, much less expensive than alternatives like rooftop tents.
As kids grow... they could move into a ground tent arrangement to help promote independence and growing camping skills.
Hope these ideas could be helpful for those looking to sleep additional people.
1. Truck Seating: Flexible
Truck can seat up to 6 people! It has a proper front bench seat (seats 3).
The front easily converts between the console and seat by flipping up/down.
The rear split fold 60/40 bench seats 3. Lots of combinations could be used here!
The rear seat is 2 separate parts. Meaning you could have 1 rear seat (60% driver side removed) or 2 rear seats (40% passenger side removed).
2. Camper Seating:
It will fit 3-4 people. Plus an additional small child may fit on the short bench side. We've also had guests sit on the bathroom floor (which is elevated and works well).
3. Camper Sleeping:
It is really a 2 person (queen bed) configuration. However, a small child would fit on the dinette seat (long side).
4. Additional Sleeping Options:
Truck Sleeping Platform! There are some configuration options here...
A) Sleep on the bench seat Front or Rear. Simple, Quick setup. It would be possible to sleep up to 2 (1 front / 1 rear).
B) Rear seat delete options. Could be entire or partial. The 60% driver side or 40% passenger side seat can be removed individually.
GooseGear has some good photos showing what it looks like in either configuration:
Goose Gear Ford Super Duty F250-F550 2017-Present 4th Gen. Super Cab - Second Row Seat Delete Plate System
The Ford Super Duty F250-F550 Second Row Seat Deletes for the Super Cab are designed for you to replace your rear seats and create a flat and secure platform to secure your gear to. The Seat Delete Plate System includes hatches that allow access to the factory storage space below the rear seats...
www.goose-gear.com
I would look to build a custom platform to maximize storage and allow for quick setup. Ideally... remove the 60% driver side (2 seats). Build a fixed platform in this area. To maximize space, platform height could match the front center console height (approx. 20" from the floor). Giving a ton of secure storage under the platform. On top of the platform foam cushions and sleeping gear could be stored.
The 20% passenger seat can fold both up (seat bottom) and down (seat back). Folding the seat back down gives the most width and matching height to the center console (ideal).
This gives around 28" of headroom above the platform which is plenty to move around.
Total width side/side is 67" which can work for many adults.
Total width (from back wall to center console) is 30" or more. With the seats forward it adds another 6" or more.
The platform could have a hinged section that would extend over the 40% passenger seat giving a flat sleeping area.
Alternatively, the entire back seat could be removed with a bike platform installed (as we used the truck). Bikes could be store outside at night; and the platform could be used for sleeping on. Then the front bench seat could be utilized for transporting the additional passenger.
Interior sleeping configurations are versatile and by far the most secure and poor weather friendly. Plus, much less expensive than alternatives like rooftop tents.
As kids grow... they could move into a ground tent arrangement to help promote independence and growing camping skills.
Hope these ideas could be helpful for those looking to sleep additional people.
Last edited:
mk216v
Der Chef der Fahrzeuge
Excellent info as always Peter!
To those interested in other feedback, having had 37s on mine with R140 6spd auto, and 4.88s, it felt good. Bit less mpg but good power (I would typically shift down a gear when coming to a larger hill). I haven't driven 37s with 4.30s to know the differences.
I also had a full 2nd row dog/gear platform, which was later modified to allow the 40% seat to fold down for 1 person (while the 60% remained a platform). See my F350 build thread for further pics.
GLWS Peter!
To those interested in other feedback, having had 37s on mine with R140 6spd auto, and 4.88s, it felt good. Bit less mpg but good power (I would typically shift down a gear when coming to a larger hill). I haven't driven 37s with 4.30s to know the differences.
I also had a full 2nd row dog/gear platform, which was later modified to allow the 40% seat to fold down for 1 person (while the 60% remained a platform). See my F350 build thread for further pics.
GLWS Peter!
montypower
Adventure Time!
Turned over the big 40k! We drive the truck every week or two. Exciting to see it roll over. Ready to go another 460k miles.
montypower
Adventure Time!
We've had several interested in the camper... Truck will likely be available by itself soon!
montypower
Adventure Time!
Getting a rig dialed takes A LOT of TIME. But it is worth it for the places and adventures.
Flexing the suspension with the Truck Camper! For the size and weight this is the most capable, comfortable travel vehicle.
montypower
Adventure Time!
Funds in process on the Camper!
Donki will be up for grabs next week. Don't miss the opportunity.