Ski Bum Truck V2.0, F450 Rough Road RV
- Thread starter java
- Start date
PNWINFERNOPRO
@PNWINFERNOPRO
Interested in your review.
pappawheely
Autonomous4X4
Looking through some old race files the other day. There it was! Caught my eye in 2015.
java
Expedition Leader
That's awesome! Glad we ditched the blue
Alloy
Well-known member
We are in the same boat. Looking at what can be done to F450/550 so we can used it for towing and a daily driver once we arrive at our destination.
Some of the options being considered:
Not sure about durability
www.autoflexsuspensions.com
Air ride for the cab
www.linkmfg.com
Four air ride seats are $$$$
www.seat-specialists.com
Expensive and takes up storage space
liquidspring.com
Not sure about durability .....think GXV has stopped using it
kelderman.com
This is the system that off road dump truck drivers like.
The easiest/cheapest option would be dropping a couple of leafs on each side and making up the difference with Airlift bags when loaded.
Some of the options being considered:
Not sure about durability
HOME | Auto / Trailer Air Ride Suspensions. Thunder Bay, ON
LBC Contracting/ Auto Flex/ Trailer Flex Air Ride Suspensions for auto and trailer.
www.autoflexsuspensions.com
Air ride for the cab
Cab Suspensions
For more than four decades, Link has been driven to outperform by engineering heavy-duty trucking solutions that raise the bar for performance, installation…
www.linkmfg.com
Four air ride seats are $$$$
Search by Truck - Ford - F250-750 - Seat Specialists
The Ford 250-750 requires an Ultra Low Profile Seat that can be selected from a variety of truck seat manufacturers | Seat Specialists
www.seat-specialists.com
Expensive and takes up storage space
Smart Suspension Vehicle Upgrade | LiquidSpring
LiquidSpring’s innovative suspension technology is a game-changer for recreational, overland, emergency, and transit vehicles. Choose a vehicle to learn more.
liquidspring.com
Not sure about durability .....think GXV has stopped using it
Kelderman Air Suspension Systems Offer Better Performance
Get a better ride with the stock height services and products we offer at Kelderman. We promise quality service and performance from the work we do. Learn more.
kelderman.com
This is the system that off road dump truck drivers like.
The easiest/cheapest option would be dropping a couple of leafs on each side and making up the difference with Airlift bags when loaded.
java
Expedition Leader
We are in the same boat. Looking at what can be done to F450/550 so we can used it for towing and a daily driver once we arrive at our destination.
Some of the options being considered:
Not sure about durability
HOME | Auto / Trailer Air Ride Suspensions. Thunder Bay, ON
LBC Contracting/ Auto Flex/ Trailer Flex Air Ride Suspensions for auto and trailer.
Air ride for the cab
Cab Suspensions
For more than four decades, Link has been driven to outperform by engineering heavy-duty trucking solutions that raise the bar for performance, installation…
Four air ride seats are $$$$
Search by Truck - Ford - F250-750 - Seat Specialists
The Ford 250-750 requires an Ultra Low Profile Seat that can be selected from a variety of truck seat manufacturers | Seat Specialists
Expensive and takes up storage space
Smart Suspension Vehicle Upgrade | LiquidSpring
LiquidSpring’s innovative suspension technology is a game-changer for recreational, overland, emergency, and transit vehicles. Choose a vehicle to learn more.
Not sure about durability .....think GXV has stopped using it
Kelderman Air Suspension Systems Offer Better Performance
Get a better ride with the stock height services and products we offer at Kelderman. We promise quality service and performance from the work we do. Learn more.
This is the system that off road dump truck drivers like.
The easiest/cheapest option would be dropping a couple of leafs on each side and making up the difference with Airlift bags when loaded.
Funny you posted. I was just writing up a rant/ramble about springs and shocks and stupid heavy trucks.....
The rear isn't all that bad with the new leaf packs. It could use some shocks, but otherwise its much better than the OE spring. I do have the bags still, and IIRC have ~30psi in them.
The front is where I am concentrating on right now. (I am on Kelderman air ride in the front)
Begin ramble...
Spring rates. you need a minimum to hold the weight up. No two ways around that. BUT with the air bags, you have to add pressure to get the height. A spring can be made taller at the same spring rate correct? Where in the air bag the spring rate is increased with air pressure. However in theory the spring rate is as low as it can be to hold the weight at X height?
Zip ties on the shock shafts show I am not using the front suspension. Nearly NOT AT ALL. When I got to the start of gravel, I hopped out, three fingers of movement on the shaft, ~2.5" uptravel.... Thats not much (and not bottoming out on the bags)
Here is after a pretty decently rough section. A bit more movement, but still not much...
I did try inflating the bags to 9" tall. No difference, a bit worse even perhaps (more spring rate...). And they sit funky on the bases like that, not happy looking.
Frustrated.
Should I go back to coils? Just try to find taller softer ones?! Anyone have an idea of spring rate needed? 6200lbs on the front axle.
Went and played on the rocks.
And to finish off the weekend..... My oil leak is getting worse.... Thought i smelled oil a little on the way home, and noticed the spots on the back doors were a bit worse this weekend.... Underside is good and oiled down now. No idea where its coming from. Its mostly at the trans/block connection it seems, upper pan (usual leak spot) looks good. could possibly be the lower pan, but it appears to be coming from higher. But perhaps its just running around the lip of the oil pan and hitting there at speed?
Shoved my phone in and took a bunch of pictures.... This one caught my eye once it was on the computer. Looks like possibly the dipstick (or whatever that tube is..)? There is no "gunk" stuck there, high flow spot?
luthj
Engineer In Residence
Of that 6200lbs, do you know how much of that is un-spring (wheels, axle)? What is your total travel? What is the desired ride height from full droop? With that information I can give you a coil spring rate estimate. From there you can work out shock valving. Given the weight you may need a fair bit of preload on the coils. This is because lower spring rates mean a softer ride. With a decent anti-sway bar you can get by with softer springs without suffering too much body roll.
If you have your shocks damping turned way up, that will sometimes restrict travel.
If you have your shocks damping turned way up, that will sometimes restrict travel.
java
Expedition Leader
I weighed before the new wheels and tires... But the new wheel and tires are 230# each. Dana Super 60 is right about 650# incl brakes knuckles etc
Total uptravel currently is ~4"
Ride height to full drop IDK, probably again in the 4" range.
So 8" total travel? (seems like too little?)
Shocks were valves to my weight and telling them I am on bags at X height. They are currently set to full soft.
Are you thinking coils may be better than the bags?
Ozrockrat
Expedition Leader
Oil leak from the dipstick is a distinct possibility. There is a fix for it without removing the pan but it’s expensive.
https://www.strictlydiesel.com/p-2690-strictly-diesel-dipstick-adapter-repair-kit.aspx
https://www.strictlydiesel.com/p-2690-strictly-diesel-dipstick-adapter-repair-kit.aspx
java
Expedition Leader
That's the 7.3 issue. Mine is an Oring into the upper pan. Thinking perhaps too ouch boost plus some blow by, killed the Oring?
Sent from my SM-G973U using Tapatalk
luthj
Engineer In Residence
Bags can ride just fine if they are sized right. But its hard to determine their effective spring rate at various pressures without more information (usually a manufactures table).
I would suggest 650-700lb springs (assuming 4" down travel from ride height). This assumes zero preload, and would put your suspension frequency at about 1.55hz. That is within the comfort range, but still firm enough to give acceptable handing.
You obviously have way too much pressure in those bags if you can't use most of your shock travel.
I would suggest 650-700lb springs (assuming 4" down travel from ride height). This assumes zero preload, and would put your suspension frequency at about 1.55hz. That is within the comfort range, but still firm enough to give acceptable handing.
You obviously have way too much pressure in those bags if you can't use most of your shock travel.
java
Expedition Leader
Here is the bag info if that helps. Running about 75-78psi ish.
How would I determine total length needed for the coil?
java
Expedition Leader
The idea of ditching the damn stiff factory coils. The Kelderman leveling kit is what Earthroamer runs, I figured that was a good starting point... It was "supposed" to make it ride much better.
But I dont know if its my long wheelbase, and heavy front or what, but it feels about the same as the stock coils, although its ~1.5" taller.
luthj
Engineer In Residence
Coil length is determined by desired ride height, and wheel position at full droop. Find the difference between the full droop position and your desired ride height. Then cacluate the springs compression based on its rate and the spring weight. For the 650lb springs that is about 4". If you have more than 4" of droop from ride height, you need a softer spring, or a droop limiting strap.
For example, you have 16" between the top and bottom spring perch at full droop. You want the ride height to be 4" lower than that . So a 650lb 16" spring does the job. Another option if you can't get the length or rate you want for the ride height, is to compress the spring with a compressor, so that the suspension has a bit of preload in the full droop position.
