Reading F350 overload springs for a 9'6" NL, stableloads

[Siletzspey]

This is my first post to the forum, and I've gotten a lot from reading prior posts. Thanks!

Question... how does one read over-leaf and under-leaf engagement and dust-wear patterns to know if one is overloaded, and if helpers are warranted?

Particulars... my 2015 F350 4x4 SRW is door-sticker rated at 3,900-lbs payload, my new 2018 Northern-Lite 9'6" QSE at half-wet with me and wife is at 3,500, and I'm predicting fully wet and loaded up to 4,400. The center of gravity is 9.5" forward of rear axle.

Driving away from the RV dealership at 3,500-lbs, the F350 handled very well, and the truck is fairly level.

Still, I'm trying to read the dust wear pattern on the rear upper-leaf overloads, and trying to speculate if torklift stableloads might be appropriate on the lower-leaf overloads, especially if I get up to 4,400. Of course I don't want to lose constant over-leaf engagement with the rubber bumper.



Thanks,

--SiletzSpey

[Powerdude]

Sticker loads are for the lawyers, give or take a few hundred pounds.

Upper stableloads, and lower stableloads are your friend.

On my F250 with a 3000 lbs camper, I switched from LT275/70R18 tires to a tire with shorter sidewall, same weight capacity at LT285/65R18.

Shorter sidewall equals less flex, less sway.

With the Upper and Lower stableloads, and the truck camper package, it's the way to go.

If you're under tire ratings for the rear axle, you are fine. That axle is good to 9600 lbs. I would not go anywhere near that on an SRW though, very few tires add up to that (if any).

[Siletzspey]

mbloof wrote:
I see you live in Oregon ...

Thanks for the reply. My best "bet" is that I'll be a little under 7,000 rear axle, under for front axle, but very close or at GVWR.

I did just install stableloads; only 2 of the 3 wedges fit the unloaded gap size. Semi-wet, the overleaf overloads now touch the rubber bumper on one end, and 1/2 inch gap on the other end.

There is a CAT scale 15mi north of me, so I plan to weight wet + fully loaded, and do a re-weigh with the water relocated to the gray and black tanks. I did discover that the freshwater tank is forward most in the truck bed, and the gray or black water 2nd most forward.

--SiletzSpey

[mbloof]

Greetings,

I see you live in Oregon so weigh stations are sprinkled all over the state on major highways. Even the closed ones still work. I use the one Near Banks Oregon off of HWY26.

I can pass on my experience although the years and numbers are a bit different. Here I have a 2014 9.6QSE recently mounted on a 2017 F250SD. The weigh stations are your FRIENDS here as without them I would not know that my 2017 is heavier than my old 1997 it replaced and that my 2017 rear end weighs 3000lbs EMPTY and 6400lbs with the camper (minus water, passenger and firewood). I'm currently rolling 11200lbs on a 10,000GVWR truck.

The rear tires on my F250 are 18" rated at 3450ea giving me 6900lbs of weight I can have on 80PSI tires. Given that with a passenger, full water and full firewood I ought to be rolling 12-13,000lbs I ordered the 19.5" rims to go with the 265/70R19.5 Toyo 608Z's (rated at 5500lbs@110PSI, overkill) that I have on the old 1997 truck.

A quick trip from Beaverton/Hillsboro to Seaside and back @ ~12.5MPG and clearly "top heavy" (as expected), more pitch and roll than with the Toyo's for sure but not over the tire weight (just the truck for now) it drove decent enough that I can imagine the improvement with the Toyo's mounted.

I believe that with these modern trucks that the tires are the weakest link and a NL is going to weigh more sitting on your truck than it looks like on paper.

(from another NL and Ford owner)

Mark0.

[Siletzspey]

Thanks for the feedback and confirmations. CAT scales and lower stableloads are in my immediate future.

--SiletzSpey

[WyoBull]

I just have the upper stableloads on my truck in addition to the AirLift 5000 Ultimate air bags and it handle great.
The upper Stableloads are very inexpensive and for carrying a camper are a no brainer in my book.

[Bedlam]

Even my 4000 lb AF811 did just fine with only the upper and lower StableLoads on my F250 with OEM stabilizer bar and 18" wheels. It wasn't till I added the trailer tongue weight that I needed more suspension, rim and tire capacity.

[Rustofer]

We have a '17 F-350 and NL 9.6 Sportsman. I added upper and lower Stableloads to both assist with handling (bounce and sway) and stance. An added benefit in the stance department is the reduced rear squat, affecting the aim of the headlights. I highly recommend the Stableloads.

[Ranger_Tim]

Well, you have what you got, so how do you want to outfit it? My '06 F350 rides like a dream with upper and lower Stableloads, but I'm only carrying 3200 lbs. fully tanked. A newer truck should have more wiggle room I think. My GVW is 11,500 and I'm about 500 under, more or less. What is more important to me is what the "seat of the pants meter" tells me in terms of drivability and stopping power. I don't wobble to and fro when pulling across pavement transitions and the wind doesn't usually bother me either. It squats only about an inch or so and it looks well balanced. How does yours compare to mine... and be brutally honest. If my hunch is correct you could probably use some suspension help. Stable loads were the answer for me, YMMV.

The way some people drive these days it doesn't matter what they do to their rigs, they're an accident waiting to happen. I work on the highways for DOT and have pushed my share of RV's off the road with a loader. Be patient, control your speed, and drive defensively -- you'll be okay. Just this week I assisted with the removal from the road of a nice, vintage Northland camper mounted on an '07 F350 SRW. He was towing a horse trailer with horses (DUH!). The rear end locked up and the truck jackknifed and fell on its side. The horse trailer stayed upright thank goodness. He was speeding, overloaded, and distracted. Ruined a really nice camper. I was impressed with how it held up though. Probably kept them from rolling.

Get some suspension help and don't set any land speed records. Try to outfit the camper with lightweight gear. And stay alert... NO texting and driving!!!

[Reddog1]

I may appear to be a bit arrogant, but my post is from seat of the pants experience, not text book. A soft sidewall tire will produce more sway. You need no degree in engineering to determine the load capacity of a tire, it is stated on the side of the tire.

You can read many things into the load capacity of given truck, but use care and get off the couch if you want to be taken seriously. Does the wheel covers really matter? Are you making statements to impress others with what you understand from what you have read?

[Kayteg1]

Siletzspey wrote:
I'll post when I have CAT scale answers.

For your entertainment, and assuming 500 beyond camper wet and 500 in the cab and Ford's curb weight specs, my final theoretical math shows 6,651 on the rear axle, 4,607 on the front axle, 11,258 total. Rear GAWR is 7,000, front 5,200, GVWR 11,000. Michelin 18" A/T2 are rated 3,640, the rims 3,590.

That suggests the rear tires will be at 91% capacity. Fresh/gray/black water shift and left/right imbalance likely imply more. I plan to diet now and shift to "lite" beer 😉

--SiletzSpey

If you have scales close enough (CAT scales offer free service if you don't need certificate) do it twice.
1 with normal stuff you'd take off from your house.
2. fill up rear holding tanks.
I bet you'll be for good surprise.

[LamboDesigns]

Siletzspey wrote:

LamboDesigns wrote:

The nerd in me would love to see a set of force vectors on the tires and wheels at various locations when going through a slalom course with different speeds, loads, and cg placements.

If the weight change on one end of an overleaf overload could be measured, along with the g-forces and potentially tilt on a camper, would that provide useful information?

I've played with sensors and data-logging on Arduinos, and see an inch-high quarter-sized load cell rated for 2,200 pounds. That said, I'm still puzzling on what meaningful data could be extrapolated.

--SiletzSpey

I guess the utility of the data would be if you go around a sweeper at 60 mph with no suspension mods and then do the same thing with various suspension mods what change would there be on the outboard tire load vs lean angle. I think you are correct that if you could plot the amount of force between the overload and perch you would get a feel for how it changes from a static load. If it is significant it could lead to a lot more folks getting on-board with mods that "don't change the sticker" but still decrease the load a given tire would receive. For me the mods make the truck much safer and easier to drive so I tend to disregard the sticker and go with what works. I've read a lot of great advise here and other TC forums and I'm at a good place with my setup.

Now as for the rest of it I would just love to see it because I'm curious:)

My son just got a bunch of Arduino stuff for Christmas so we are going to start playing with it to see what all we can come up with. We've been doing a lot of racing at K1Speed so I'd love to have a TM setup on the karts to know just where we are loosing speed. My wife and I were both engineers on weapon systems back in the day so he gets the engineering nerd gene times 2 and the system engineer in me can never have too much data. We are building a man cave for him in the attic to work on projects so as soon as that is done we will start on the Arduinos. Speaking of man cave.... I better get back at it. I'm almost done with the flooring:)

Oh... have you seen the new esp8266 Arduino boards that have the wifi built in? For around $8 those are dirt cheap and have so much potential for projects. The lego robotics team was using them for their projects. One was to put a flow meter on the shower head and then send an email with the amount of water used per shower. Would be kinda cool to track all the water consumption in a RV that way.

[Siletzspey]

LamboDesigns wrote:

The nerd in me would love to see a set of force vectors on the tires and wheels at various locations when going through a slalom course with different speeds, loads, and cg placements.

If the weight change on one end of an overleaf overload could be measured, along with the g-forces and potentially tilt on a camper, would that provide useful information?

I've played with sensors and data-logging on Arduinos, and see an inch-high quarter-sized load cell rated for 2,200 pounds. That said, I'm still puzzling on what meaningful data could be extrapolated.

--SiletzSpey

[Siletzspey]

I'll post when I have CAT scale answers.

For your entertainment, and assuming 500 beyond camper wet and 500 in the cab and Ford's curb weight specs, my final theoretical math shows 6,651 on the rear axle, 4,607 on the front axle, 11,258 total. Rear GAWR is 7,000, front 5,200, GVWR 11,000. Michelin 18" A/T2 are rated 3,640, the rims 3,590.

That suggests the rear tires will be at 91% capacity. Fresh/gray/black water shift and left/right imbalance likely imply more. I plan to diet now and shift to "lite" beer 😉

--SiletzSpey

[LamboDesigns]

emcvay wrote:

Reddog1 wrote:


If you modify the overload springs to make contact sooner, it will only reduce the amount the rear of the truck squats when loaded. The same amount of weight is on the tires.


Wayne

This is not my understanding. What engaging the overloads does is ensure a more stable ride because when cornering the overloads, as stock, can disengage causing more sway and bounce. If you watch the torklift videos it's quite interesting.

Adding this does not change your capacity but does make heavy loads more manageable. At least so it seems when doing the research I've done.

Wayne... with a static load you are correct but with a dynamic load (sway, etc.) you will load and unload from side to side as emcvay said. The more you can keep the load centered over all the tires the better. Not really a sticker for it but you could say worst case is that in a hard corner with the truck leaning way over almost all the weight is on 2 (3) tires with the other 2 (3) along for the ride. The nerd in me would love to see a set of force vectors on the tires and wheels at various locations when going through a slalom course with different speeds, loads, and cg placements.