Tow Rig Scale Numbers.

[skegpro]

2015 Ford F350 diesel crew cab 4x4
22" alcom aluminum car hauler

Stopped at the scales on the way home.
Drove 1000km in a blizzard.

Truck and trailers was loaded up with ice+snow as per usual.

Sled deck in the box.

1/4 tank of diesel.

2 sleds in the trailer.
Sleds outta fuel, all Jerry cans empty.

Truck = 10,008 lb
Front axle = 4850 lb
Rear axle = 5533 lb

Trailer = 5423 lb
Front axle = 2711 lb
Rear axle = 2469 lb

GCVW = 15,431 lb

Stopped to check and make sure the weight distribution on the trailer axles was equal. I spent some time messing with hitch height to achieve this, tows very well now.

Thought someone might find the numbers interesting.

 

[AaronQ]

Were you getting some bounce in the tongue and a little wiggle out of the trailer?

 

[52weekbreak]

Assuming I am reading the specs correctly (a bit of a Gamble) you are well within The limits allowed. Given the relatively light trailer load, one could be forgiven for assuming trailer angle shouldn't be an issue. How much did you raise or lower the hitch. I am assuming the final position was level or ???

 

[skegpro]

Were you getting some bounce in the tongue and a little wiggle out of the trailer?

Yes, raised my hitch up one inch to get the axle weights balanced.

No more bounce or wiggle, truck sits just barley touching the overload springs.

Took a bit of weight off the truck.
Truck sits level, lights are not pointed to the sky anymore.

Improved fuel economy a bit.

Less stress, pulls like a dream.

 

[AaronQ]

Got air bags on the truck?
It's amazing how much even moving the machines in the trailer forward or back a few inches can change the load on the tongue.

 

[skegpro]

Assuming I am reading the specs correctly (a bit of a Gamble) you are well within The limits allowed. Given the relatively light trailer load, one could be forgiven for assuming trailer angle shouldn't be an issue. How much did you raise or lower the hitch. I am assuming the final position was level or ???

Yes, I think I am legal.
Will have to look at my door sticker when I get a chance.

Trailer definitely squats the truck down, so I am getting good weight on the rear axle.
I am about 1/2 of GVW on the trailer, when loaded and iced up.

When the trailer is dry and unloaded it sits 1.5" higher in the nose than the rear of the trailer.

When loaded and iced up I am darn near perfectly level from to back now.

Before I started out level, empty/dry.
Loaded I would be low 1-2" in the nose.
That's when I noticed it wouldn't pull as nice.

Used to really bounce when hitting a frost heave.

 

[skegpro]

Got air bags on the truck?
It's amazing how much even moving the machines in the trailer forward or back a few inches can change the load on the tongue.

I was just about to add airbags but decided to try this first.

Glad I did.

I have had airbags before in other trucks and find that if you have to run much pressure in them to level the ride really goes to ****.

 

[skegpro]

Got air bags on the truck?
It's amazing how much even moving the machines in the trailer forward or back a few inches can change the load on the tongue.

And yes sled placement makes a huge difference.

We drive two in and back two in.
So they pretty much cancel each other out distribution wise.

When I weighed this I had one driven in and one backed in.

 

[AaronQ]

I was just about to add airbags but decided to try this first.

Glad I did.

I have had airbags before in other trucks and find that if you have to run much pressure in them to level the ride really goes to ****.

Ya it's a fine line if they help a ton or not. They're an option I think I'd always put on a truck even if just for the weekend you throw the sled deck on or have the box loaded right up. Takes a lot of the sway out when decking.

 

[skegpro]

Assuming I am reading the specs correctly (a bit of a Gamble) you are well within The limits allowed. Given the relatively light trailer load, one could be forgiven for assuming trailer angle shouldn't be an issue. How much did you raise or lower the hitch. I am assuming the final position was level or ???

Whoa, I am within 1500lbs of my max GVWR, alot closer than I thought.

Had just dropped my passengers off along with two sleds. Weight of the passengers will definitely subtract from that 1500lb but the sleds shouldn't add much hitch weight.
Plenty of excess GVWR on the trailer.

Looks like I won't be adding a slip tank and my passengers can't getting any bigger.
Lol

 

[ippielb]

Wow that trucks super heavy! My Duramax is under 7,000 pounds empty. Lol

didnt realize you had a sled deck and trailer hooked on. Oops

 

[OVERKILL 19]

I have had airbags before in other trucks and find that if you have to run much pressure in them to level the ride really goes to ****.

You can let air out of them......js

 

[ABMax24]

2015 Ford F350 diesel crew cab 4x4
22" alcom aluminum car hauler

Stopped at the scales on the way home.
Drove 1000km in a blizzard.

Truck and trailers was loaded up with ice+snow as per usual.

Sled deck in the box.

1/4 tank of diesel.

2 sleds in the trailer.
Sleds outta fuel, all Jerry cans empty.

Truck = 10,008 lb
Front axle = 4850 lb
Rear axle = 5533 lb

Trailer = 5423 lb
Front axle = 2711 lb
Rear axle = 2469 lb

GCVW = 15,431 lb

Stopped to check and make sure the weight distribution on the trailer axles was equal. I spent some time messing with hitch height to achieve this, tows very well now.

Thought someone might find the numbers interesting.

Your numbers don't make sense to me, 4,850+5,533 doesn't equal 10,008, its 10,383. If this is the case you're actually closer to max payload.

 

[skegpro]

Your numbers don't make sense to me, 4,850+5,533 doesn't equal 10,008, its 10,383. If this is the case you're actually closer to max payload.

Yeah I added that up and noticed that too.
All I did was write down the numbers.

Front truck axle on,
Then both truck axles,
Then rear truck axle,
Then front trailer axle,
Then both trailer axles,
Then rear trailer axle.

I think when I dropped the front axle off and had just the rear axle on the scale it was now the high point so weight transferred a little.

 

[ABMax24]

Yeah I added that up and noticed that too.
All I did was write down the numbers.

Front truck axle on,
Then both truck axles,
Then rear truck axle,
Then front trailer axle,
Then both trailer axles,
Then rear trailer axle.

I think when I dropped the front axle off and had just the rear axle on the scale it was now the high point so weight transferred a little.

Most likely, are you running a weight distributing hitch?

 

[skegpro]

Your numbers don't make sense to me, 4,850+5,533 doesn't equal 10,008, its 10,383. If this is the case you're actually closer to max payload.

So not to go full instrumentation techno dork on you but another thing to consider is the accuracy spec on the scale.

(383lb error/10,008 lb) x 100 = 3.83 % error

most industrial scales have an accuracy spec of +/- 1% of reading if i remember correctly.

4,850lb x 1% = +/-48.5 lb x 2= 97.6lb
97.6 lb/4850lb x 100 = 2% error

5,533lb x 1% = +/- 55.3 lb x 2 = 110.6 lb
110.6 lb / 5533lb x 100 = 2 % error

10,008lb x 1% = +/- 100.08 lb x 2 = 200.16 lb
200.16 lb / 10,008 lb x 100 = 2% error

10,383lb x 1% = +/- 103.83 lb x 2 = 207.66 lb
207.66 lb / 10383 lb = 2% error

If a guy actually calculated the root sum of squares of the 3 measurement's possible errors I think being out 383lbs is almost within within the accuracy statement of the scale.

sqrt= [(2)^2 + (2)^2 +(2)^2]
sqrt= [ 4 +4+4]
sqrt = [12]
= 3.46% Total Error

10,008 lb x 3.46% = 346 lb of error

There is always less precision when adding multiple measurements together because the inaccuracy of each measurement has to be taken into account.
Best just to try and drive the whole rig on a scale.

But the weight probably also transferred a little bit because the scale surface is elevated a wee bit from the rest of the deck.
Or the scale could be due for a calibration.......

 

[skegpro]

Wow that trucks super heavy! My Duramax is under 7,000 pounds empty. Lol

didnt realize you had a sled deck and trailer hooked on. Oops

and I melted a small Glacier in my shop.

 

[skegpro]

Most likely, are you running a weight distributing hitch?

No just a regular hitch.

 

[ABMax24]

So not to go full instrumentation techno dork on you but another thing to consider is the accuracy spec on the scale.

(383lb error/10,008 lb) x 100 = 3.83 % error

most industrial scales have an accuracy spec of +/- 1% of reading if i remember correctly.

4,850lb x 1% = +/-48.5 lb x 2= 97.6lb
97.6 lb/4850lb x 100 = 2% error

5,533lb x 1% = +/- 55.3 lb x 2 = 110.6 lb
110.6 lb / 5533lb x 100 = 2 % error

10,008lb x 1% = +/- 100.08 lb x 2 = 200.16 lb
200.16 lb / 10,008 lb x 100 = 2% error

10,383lb x 1% = +/- 103.83 lb x 2 = 207.66 lb
207.66 lb / 10383 lb = 2% error

If a guy actually calculated the root sum of squares of the 3 measurement's possible errors I think being out 383lbs is almost within within the accuracy statement of the scale.

sqrt= [(2)^2 + (2)^2 +(2)^2]
sqrt= [ 4 +4+4]
sqrt = [12]
= 3.46% Total Error

10,008 lb x 3.46% = 346 lb of error

There is always less precision when adding multiple measurements together because the inaccuracy of each measurement has to be taken into account.
Best just to try and drive the whole rig on a scale.

But the weight probably also transferred a little bit because the scale surface is elevated a wee bit from the rest of the deck.
Or the scale could be due for a calibration.......

I remember reading somewhere that road scales should be accurate to +/- 1 Limit of Error if weighing under 5000kg. i.e if the scale shows in 10kg graduations then it needs to be accurate to +/- 10kg. Which is far less than +/- 1%. If only I could find the datasheet I found that on...

 

[skegpro]

I remember reading somewhere that road scales should be accurate to +/- 1 Limit of Error if weighing under 5000kg. i.e if the scale shows in 10kg graduations then it needs to be accurate to +/- 10kg. Which is far less than +/- 1%. If only I could find the datasheet I found that on...

Yeah I couldn't find any data on the hwy scales, just used the numbers from the last 65 Ton scale I worked on.

Regardless if it's 1% or 0.2% my numbers are still in the ballpark however you wanna explain why the axle weights don't translate 100% to the sum of the total vechiles weight.