Towing help (weight)

[timf343]

Hi guys, hoping one of you guys with alot of towing experience can help me out here. 6.7L F350 tremor stock suspension. Bought a cargo trailer that sits on two 7k axles, derated to 9990 to keep me under the CDL limit. Filled it with stuff and took it to the scales. The weights.....

	Truck alone	Truck with trailer	Difference
Steer	5420	4420	-1000
Drive	4300	7880	3580
Trailer	0	9080	9080
Total	9720	21380	11660

So a couple issues:

1.) At first I thought trailer was only 9080, but that's all that's on the axles. The rest of the weight sits on my truck. So technically the trailer is 11,660 lbs.

Am I technically overweight on the derate or is it OK since the truck is holding some of it?


2.) Tongue weight is 3580 lbs. I already know this is way too heavy. Plus it's more than 30% of the trailer weight. I need to move shit around in the trailer to put more heavy stuff in the back and try to get in the 10-15% sweet spot.

Can I fix this by simply ADDING weight to the rear? Say a dozen cases of water (~500 lbs) at the very back of trailer?

What is the math for figuring out how much weight I need to move?


3.) Front is -1000. I figure this is a side effect of the heavy tongue and this will return closer to normal once I move things, but how much weight should I expect to lose (if any) on the front when towing? How much is unsafe?


Thoughts? Advice?

 

[oops]

By my estimation:

1. Yes, you're over weight.

2. Maybe.

You need to be careful using a rear ballast alone to shift the center of mass in your trailer.

Here's an article addressing the various bits of advice you'll receive on this with appropriate caveats: https://www.weigh-safe.com/towing-safety/how-to-properly-load-your-trailer/

At the end of the day, most folks will go off of “look & feel” of a truck/trailer they're accustomed to. And some validate those instincts with a Weigh Safe tongue weight scale.

3. Hard to say.

That comes down to the weight distribution of our trucks themselves. A way to back into that number is to go by hitch or pin weight.

For example, all of our trucks have a maximum convention tow rating of 15,000#. And Ford says the hitch weight should be 10% of that trailer weight (Page 47 of the Towing Guide). So Ford says you're safe to put up to 1500# on your bumper hitch. Any more than that and you're outside of Ford's guidance, and safety becomes a question of personal tolerance.

 

[oops]

paging @ccw who may be willing to nerd out further on the above.

 

[Guest6749]

If you suspect you are already overweight, adding weight to move the cg of your trailer sounds like a shitty idea to me...

 

[Modman]

2.) Tongue weight is 3580 lbs

You have also transferred 1000lbs from the front... so if nothing else has changed in the weight of your truck or it's contents, your tongue would = 2580lbs.

Your trailer weighs 11,660lbs, again, assuming nothing else has change with the truck and contents. So, yes you are overloaded.

2580/11660 = 22% tongue which is still on the high side.

The best way to address this is to move heavier items in the trailer over it's axles vs. near the front. There is no magic, just trial and error.

For instance, if you removed the extra 1670lbs to get you back to 9990 AND that was all sitting near the front of the trailer you would now have:

(2580-1670)/9990 = 9% tongue.

In reality you probably would not take all 1670lbs directly off the tongue. Let's say, for argument sake, that 80% of that would be removed from the tongue weight if you removed it from the trailer. Then you would be left with:

(2580-(.8*1670))/9990 = 12.5% Tongue

What this means is that your problem is the fact that you have:
1) Too much weight in the trailer vs. your rating
2) The weight in the trailer is biased too far forward for proper tongue weight guidelines
3) The extra tongue weight on the hitch is transferring too much weight from front to rear on the truck

Your payload for the truck should also be checked. If your truck is 9720lbs and your GVWR is 11,800 that also means you are over your max payload. 9720+2580 = 12,300

 

[ccw]

paging @ccw who may be willing to nerd out further on the above.

Well, I was typing up a response and then @Modman beat me to it and made all of my points.

Only other thing I will add is to watch the rear GAWR. I'm pretty sure the rear GAWR is 6950 pounds for your truck (that's what it is for mine; check your door sticker), which means you're currently 900+ pounds over that weight. GAWR is widely considered to be more important than GVWR. Correcting for the heavy tongue weight should fix that, but just be sure to keep an eye on it.

 

[DIG]

I think your pin weight is actually 2580lbs. 11660-9080= 2580. I just saved you 1,000 lbs of payload.

Edit: @Modman and @ccw beat me to it.

 

[Modman]

Well, I was typing up a response and then @Modman beat me to it and made all of my points.

Modman - 1
@ccw - 1000

 

[timf343]

Thank you, a lot of great information here. Thanks for pointing out my math error on tongue weight. It didn't occur to me at first (obviously), but it makes sense now thanks to the explanations.

Regarding GAWR, that was also of chief concern to me. When I got the weigh ticket, my jaw dropped when I saw nearly 4 tons on the rear. Mine's limited to 6830. So I am way over. I'm glad the scales were only 2 miles from where my trailer is parked so I didn't take it too far like that. On that topic though, my front GAWR is only 5200 and the only thing I put up there is a Ranch Hand bumper, otherwise stock and I'm 220 lbs overweight there unloaded. Yikes.

I'll report back tomorrow after I re-balance and re-weigh.

 

[Modman]

@timf343 The other thing I was going to ask is what all is in your truck? I thought a stock F350 6.7L Tremor would be in the ~8100 neighborhood + additional driver weight and then other cargo... so you must have another ~1500lbs of "stuff" in your truck (including the Ranch Hand)?

 

[timf343]

@timf343 The other thing I was going to ask is what all is in your truck? I thought a stock F350 6.7L Tremor would be in the ~8100 neighborhood + additional driver weight and then other cargo... so you must have another ~1500lbs of "stuff" in your truck (including the Ranch Hand)?

Yea, she's a heavy truck.

Ranch Hand bumper is 276 lbs. Another 104 for the winch is 380 lbs on the front.

I also have a 50 gallon TransferFlow tank in the bed. That's ~170 lbs. Plus the 50 gallons of diesel in the tank is 355 lbs. Another 34 gallons in the OEM tank is 240 lbs. Total 765.

I'm about 320 lbs myself. And I carry around 15 gallons of water (mostly in bottles, distributed to all the doors and a cooler in the back) for another 120 lbs.

So that's 1585 of stuff. When I add my girl, 2 dogs (and dog food) plus our suitcases for this upcoming trip, we'll be right around 2000. My truck has a cargo capacity of 3285, leaving around 1285 remaining.... so that's my target number for tongue weight max, assuming I can get that GAWR down to within spec too.

I never knew truckin it involved so much dang math.

 

[ccw]

I never knew truckin it involved so much dang math.

Easy way to avoid that is go for massive overkill. Get yourself a semi to haul and tow your stuff and you won't have to math it out at all.

Ranch Hand bumper is 276 lbs

Pretty minor nitpick since it won't change the big picture, but if the bumper itself is 276 pounds remember that you only added the difference between that and the factory bumper, whatever it weighs.

But ya, big picture is that weight adds up surprisingly fast and no question you've got a lot of extra weight.

 

[timf343]

So I had a crew unpack and repack the trailer for me and we were able to easily eliminate 1,160 lbs in cargo as well as get it rebalanced. I was astounded with the results. More than 1500 lbs came off the rear axle!!

	Original	Repacked	Difference
Steer	4420	4760	340
Drive	7880	6370	-1510
Trailer	9080	9090	10
Total	21380	20220	-1160

So in summary, I'm safe but not legal:

	Limit	Current
Truck GVWR	11500	11130	GOOD
Front GAWR	5200	4760	GOOD
Rear GAWR	6830	6370	GOOD
Trailer GVWR	9990	10500	OVER LIMIT 510
Tongue Weight	1050 - 1575 (10-15% of 10500)	1410 13.4%	GOOD

I don't know if I can find another 510 lbs to lose in the trailer.

With my total weight (20220) under the combined GVWR (11500 + 9990 = 21490) and the the trailer axles a full 900 lb under the limit, what is my first weigh station experience likely to be? Will they want to see my registration cards for truck & trailer? Will they make an assumption on trailer weight based on axle weight + estimated tongue weight? Will they see me under the 26000 lb CDL limit and wave me on? Do I just blow past the station and plead ignorance if pulled over?

I really can't thank you guys enough. Your advice was spot on. Moving all the heavy shit to right over the trailer axles made a huge difference. Skirting the edge of the law is one thing, but there was no way I felt comfortable driving that trailer as front heavy as it was. I could have killed my truck or my family. And I thank you for helping me get it safe.

 

[cookiemonster]

So I had a crew unpack and repack the trailer for me and we were able to easily eliminate 1,160 lbs in cargo as well as get it rebalanced. I was astounded with the results. More than 1500 lbs came off the rear axle!!

	Original	Repacked	Difference
Steer	4420	4760	340
Drive	7880	6370	-1510
Trailer	9080	9090	10
Total	21380	20220	-1160

So in summary, I'm safe but not legal:

	Limit	Current
Truck GVWR	11500	11130	GOOD
Front GAWR	5200	4760	GOOD
Rear GAWR	6830	6370	GOOD
Trailer GVWR	9990	10500	OVER LIMIT 510
Tongue Weight	1050 - 1575 (10-15% of 10500)	1410 13.4%	GOOD

I don't know if I can find another 510 lbs to lose in the trailer.

With my total weight (20220) under the combined GVWR (11500 + 9990 = 21490) and the the trailer axles a full 900 lb under the limit, what is my first weigh station experience likely to be? Will they want to see my registration cards for truck & trailer? Will they make an assumption on trailer weight based on axle weight + estimated tongue weight? Will they see me under the 26000 lb CDL limit and wave me on? Do I just blow past the station and plead ignorance if pulled over?

I really can't thank you guys enough. Your advice was spot on. Moving all the heavy shit to right over the trailer axles made a huge difference. Skirting the edge of the law is one thing, but there was no way I felt comfortable driving that trailer as front heavy as it was. I could have killed my truck or my family. And I thank you for helping me get it safe.

Check laws of the states you're driving in for weigh station rules. It'd mostly depend on how commercial you look driving down the road whether or not you'd get pulled over for weight.

Check your trailer brakes and make sure you've got them set correctly.

 

[oops]

I would not expect you would have to stop at a weigh station, or that anyone will pay you any mind, with a pickup truck and a small cargo trailer.

And from a safety perspective, you’re hauling a relatively insignificant amount of weight. Your truck will barely notice it.

Your problem was just weight distribution, and stickers.

 

[oops]

Oh, and your one remaining sticker issue, being over trailer weight rating, I *personally* wouldn’t worry about at all.

You’re well under the carrying capacity of your trailer, which is at least 25% higher than the combined axle ratings.

You’re well within the capabilities of both the trailer and the truck. And you’re within CDL limits.

Most would give that no further thought.

 

[timf343]

Oh, and your one remaining sticker issue, being over trailer weight rating, I *personally* wouldn’t worry about at all.

You’re well under the carrying capacity of your trailer, which is at least 25% higher than the combined axle ratings.

You’re well within the capabilities of both the trailer and the truck. And you’re within CDL limits.

Most would give that no further thought.

Thank you, this is where I was in my thinking as well. I appreciate your experience and feedback validating my thought process. I'm ready to hit the road.

 

[Vee8Thunder]

The one issue I'd add (and it's been beaten to death in other threads, I realize) is that if you are in an accident while pulling an overloaded trailer (defined by the rated sticker weight), you can be assured that insurance companies will try to use that against you in a civil damages proceeding if the fact is noted in the accident investigation. You can try to say "but it's been derated so it was fine", and their first question will be "are you a licensed engineer?" If your answer to that is no...it's going to be downhill from there. If you never get into an accident...this is a non-issue. But nobody plans on getting into an accident. Just my 2cp.