Can weight put on pin provide trailer axle cargo weight leeway?

Erika

Member
I'm a new Cyclone owner, full-timing and about to make my first big move and now realizing that, after add-ons such as additional air conditioner, bigger refrigerator, dual panes, etc., the rig weighs 1400 lbs more than the base model. This means that I am that much closer to my GVWR and now am not sure that I have enough capacity for my Scion IQ to ride in the garage, after factoring in my other cargo (clothes, dishes, grill, hoses, etc).

Sticker says I'm at 15500, GVWR is 18000, Scion is 2130. That means I only have around 300 lbs for cargo. I have not weighed the rig since bringing our personal items on board. I can only hazard a guess of maybe 1500 lbs in personal stuff. (?) Also, we would travel with all tanks empty and nearly empty propane.


I know that this may be a stupid question, but I cant find any discussion of it, so I thought I would just ask:

Does the amount of weight that is placed on the tow vehicle's axle via the pin provide any leeway on the amount of weight available on the axles for cargo in the trailer while it is being towed? (Scion would only be on board for travel, rolled out when we get there and then we would unhitch)

If there is around 3600-4500 lbs of weight being held by the pin in the truck bed (20-25% of 18000), does that mean that there is some weight that is being taken off of the trailer's axles (3 X 6,000), thus increasing the cargo capacity for the trailer by shifting onto the truck's axle instead?

I feel certain that the truck can handle the weight (tow package, exhaust brakes, 2014 Ram 3500 DRW 6.7L Cummins). Rated (used my VIN to confirm with my specs on Ram website) at 30,000 GCVW, about 9,000 of truck, hitch and passengers leaves 21,000 of tow capacity. Max payload of 5,650 (200 lb hitch plus pin weight wouldn't surpass that).

I also feel certain that the garage floor and ramp can handle the Scion (4000 lb ramp rating, 3500 lb garage floor rating) and we have ratchet straps & chocks to hold the Scion still. It is the trailer axles/tires/etc that I am concerned about.

Any thoughts / reactions would be appreciated.
 

Bohemian

Well-known member
GVWR is the maximum total weight of the loaded trailer. It's that simple..

The total weight may be divided up between the axles and the pin. Each of those has a maximum and also may not be exceed. Moving items forward will increase the pin weight and decrease the axle weight. Moving them back will increase the axle weight and decease pin weight.

Moving items has no effect on total weight and the relationship to GVWR.
 

danemayer

Well-known member
The GVWR of 18,000 is intended to be the max regardless of how it's distributed. Practically speaking you might be more interested in knowing the weakest link. Is it tires? Wheels? Axles? Frame? Something else? I don't think anyone knows.

But we can guess that some tires can be a weak link. Some axles as well. So the less weight on those components the better, assuming truck payload is ok.

Of course, putting a heavy toy in the garage will tilt the weight distribution away from the pin and onto the axles, etc. so with toy haulers actual weight will be much more useful than 20-25% estimates.

Also, you should look up 5th wheel towing capacity for your specific truck configuration. It varies quite a bit. My 2014 is nowhere near the max that Dodge advertises. Payload is on the door frame sticker.

Sent from my iPad using Tapatalk HD
 

Erika

Member
Thanks for the replies. Ok. Let me simplify:

My rig has 3 axles. Each axle is rated to 6,000 lbs. 3 times 6,000 equals 18,000. The GVWR is 18,000. Why wouldn't the weight that is going onto the truck's axle, thus coming off of the rig's axles (and wheels/tires) allow for leeway in the GVWR? Is it the frame that can't handle the weight? Something more complicated related to physics?

I understand that the GAWR of the rear axle would still be an issue, if the weight of the empty rig is more than the difference between 6,000 and the 2,200 for the Scion, but I'm trying to understand why the GVWR doesn't allow for some weight on the pin, as well as the three axles.

As mentioned in my original comment, I used my specific VIN to check payload, towing, GCVWR of my specific truck.
 

Bohemian

Well-known member
Thanks for the replies. Ok. Let me simplify:

My rig has 3 axles. Each axle is rated to 6,000 lbs. 3 times 6,000 equals 18,000. The GVWR is 18,000. Why wouldn't the weight that is going onto the truck's axle, thus coming off of the rig's axles (and wheels/tires) allow for leeway in the GVWR? Is it the frame that can't handle the weight? Something more complicated related to physics?

I understand that the GAWR of the rear axle would still be an issue, if the weight of the empty rig is more than the difference between 6,000 and the 2,200 for the Scion, but I'm trying to understand why the GVWR doesn't allow for some weight on the pin, as well as the three axles.

As mentioned in my original comment, I used my specific VIN to check payload, towing, GCVWR of my specific truck.

The maximum weight of the trailer may be up to the GAWR.

The maximum weight on the 5h wheel hitch may be up to the maximum rating of the pin box/frame, or the hitch or the remainder of the maximum payload of the truck (after subtracting the options and items you load into the truck including the hitch and it's supports) whichever is smallest.

The maximum weight on the axles may be up to the rating of the axles or the frame or the trailer which ever is the smallest.
 

Garypowell

Well-known member
If you are traveling with someone let them drive the car until you can run across a scale and see actual weights. Then that night run the car in if OK.

You will be overweight but at least you'll know by how much.

i think many/most of us either are at the limit or over....it is really how comfortable you are for the condition you are in.
 

Bohemian

Well-known member
or

You cold simply decide to be safe and legal, stay within the limits, and get vehicles with sufficient capacity..
 

danemayer

Well-known member
I'm trying to understand why the GVWR doesn't allow for some weight on the pin, as well as the three axles.
GVWR does allow for 20-25% of the weight to be on the pin. So if you're carrying 3,000 lbs of pin weight on the hitch, the axles are carrying the other 15,000 lbs. Therefore the axles/wheels/tires may not be carrying the maximum that they're rated to carry.

But the engineers who designed the trailer stopped at 18,000 GVWR for some reason. They haven't disclosed what part of the trailer won't handle additional weight. Perhaps it's the frame. Maybe the brakes. Maybe the additional weight would cause excessive flex on the frame that would damage the sidewalls. Those are just wild guesses. None of us knows.

If you overload a bit, will something go wrong? I don't think any of us know what the limits are, other than to say that the GVWR is the limit that's been specified.
 

scottyb

Well-known member
There are many 2 axle 5th wheels that have a GVWR higher than it's axle capacity, including Heartland's. The 4200 comes standard with 3 x 6K axles and has a GVWR of 20K. When these 3 axle rigs 1st hit the market, none of the Big 3 were making a pickup that could tow over 18K. Why spec something that eliminates 75% of your potential buyers. Most people are not willing to go to a MDT or HDT to haul their 5th wheel. As the pickup's tow ratings go up, the GVWR's of the 5th wheels will eventually follow. It's just pencil whipping.
 

Erika

Member
But the engineers who designed the trailer stopped at 18,000 GVWR for some reason. They haven't disclosed what part of the trailer won't handle additional weight. Perhaps it's the frame. Maybe the brakes. Maybe the additional weight would cause excessive flex on the frame that would damage the sidewalls. Those are just wild guesses. None of us knows.

Thank you, DaneMayer, and others, for at least attempting to answer my question. I'm just trying to understand the situation so that I can make the best decision about how to proceed. I'm frustrated that the unit is advertised as having a 3500 lb garage cargo capacity, a ramp that will hold 4000 lbs, when the rig as a whole could never hold those amounts, unless it was stripped down to bare minimums and had literally no other cargo on board. I realize now that it was unwise of me to overlook the added weight of the extra air conditioner, dual panes, etc. I don't know why it didn't occur to me to think of the weight of those items. I certainly didn't have a salesperson who was helpful in that regard, even though I told him exactly what I was hoping to do.

Bohemian, thanks for your replies, although they did come off as condescending. You may as well have just told me to eat cake, Madame Antoinette.
get vehicles with sufficient capacity..

My vehicles are fine. I am trying to be safe. That's why I'm asking, to try to understand what the risks might be. I went through everything that I have on board and weighed everything. I would only be literally a few hundred pounds over, which is a tiny percentage of the whole capacity of the rig, not to mention the combined weight.

By the way, I see that you are planning on getting the exact same truck that I currently have, so it seems you think that truck has good capacity.
 

Bob&Patty

Founders of SoCal Chapter
Erika, take your CY and weight it with all your personal stuff loaded. Then go from there. No one is perfectly legal on pin weights. Your truck should be just fine. Your "tiny car" will remove pin weight when loaded, but will add weight to the axles and to the GVW. The biggest worry you have is with the tires your CY came with. If they are "towmax" replace them now with a good "G" rated tire. Won't be cheap...but neither is replacing to side of your CY. The Goodyear G614 is a good tire to use. I have never read anything about frames failing on any CY. We have people hauling Smart cars in there CY with no problems.
 

Bohemian

Well-known member
Thank you, DaneMayer, and others, for at least attempting to answer my question. I'm just trying to understand the situation so that I can make the best decision about how to proceed. I'm frustrated that the unit is advertised as having a 3500 lb garage cargo capacity, a ramp that will hold 4000 lbs, when the rig as a whole could never hold those amounts, unless it was stripped down to bare minimums and had literally no other cargo on board. I realize now that it was unwise of me to overlook the added weight of the extra air conditioner, dual panes, etc. I don't know why it didn't occur to me to think of the weight of those items. I certainly didn't have a salesperson who was helpful in that regard, even though I told him exactly what I was hoping to do.

Bohemian, thanks for your replies, although they did come off as condescending. You may as well have just told me to eat cake, Madame Antoinette.

My vehicles are fine. I am trying to be safe. That's why I'm asking, to try to understand what the risks might be. I went through everything that I have on board and weighed everything. I would only be literally a few hundred pounds over, which is a tiny percentage of the whole capacity of the rig, not to mention the combined weight.

By the way, I see that you are planning on getting the exact same truck that I currently have, so it seems you think that truck has good capacity.

Yes, straight forward technical information can sound condescending.
 

Erika

Member
Thanks for the reply, Bob&Patty. I did spring for the upgraded tires when I ordered it off the order sheet. It says "Goodyear G-rated tires" on the spreadsheet.

I do plan to take the rig without the Scion on board to the CAT Scales, which are only a few miles away, just to see where we are before I go out on the road with the car inside. I have gone through every closet, cabinet, compartment, drawer, etc (including everything from dog toys to toothpaste to ice cubes in the freezer) and methodically weighed everything by hand. I see that we have around 1400 lbs of cargo. I can probably convince my husband to move some more things into our storage unit before we leave, so I might be able to lighten up a bit.

I appreciate those of you who have offered information for me to use in understanding what the real risks are (potential tire problems, potential flex problems affecting the sidewalls, etc)
 
I have been reading this post for a few days and wondering if i can offer anything.

First thing i was thinking was the only way to find out what everything weights, is take it to the scales. The second, is the only way to find out about any problems with adding loads, is to drive it.

I read you were going to weigh it without the Scion. that's a good idea and a good data point to have. But if you will be traveling with it loaded, you also need that weight also. Having the Scion on board will most likely change the way the RV tracks, possibly dramatically.

I also looked at the weight of your Cyclone. Interesting that the axles can handle the entire GVWR of 18,000#. That would be bad of course because you need pin weight to properly balance the trailer load. You could just imagine what would happen if all the weight was on the axles and you where to accelerate or brake or go over rough road and impose a rapid change in truck bed load or even lift the truck off the road going over rough roads. The DRW ram has several thousand more pounds of load capability on the rear axle than it's rated payload and can handle any extra weight you would get when braking with max pin weight. I'm new at pulling a 5th wheel, but it didn't take long to figure out i wanted to load as much pin weight as i could without exceeding the truck's payload spec. That might take more than one trip to the scales and redistributing loads.

There had been some problems with frame cracks on the early Lippert frames near the pin box, but i think that was sorted out and i don't see any specs on max pin weights.

The best place for the Scion's extra weight would be over the trailer axles. That's not possible of course. You can speculate all you want about what your pin weight is, but the only way to do that is on a scale. You would need to weight with everything loaded including the truck with passengers and a full tank of fuel. You have concerns about adding the Scion, getting weights with and without the Scion would be helpful. You would also have to un-hook and re-weight just the Ram 3500 and passengers to find out your pin weight, and the GVWR of the truck and GVWR of the Cyclone.

My wife and i just had that discussion the other day about GVWR and GCVW and first thing she said was "everyone she talked too is very confused". Or i should say i had that discussion.......and she tolerated it.

I am too whenever someone presents a good enough question that i have to look at my notes i took reading "Title 49 U.S.C

First thing i saw was it was written for "commercial transportation".

Second thing i noticed, was it was it's purpose was to make uniform, our State traffic laws. It basically made your driver's license from whatever state you reside in, legal in all states. And doing so, the States were then able to have some of that federal gas tax money come back to them for road repairs.

This was one of the greatest laws thought out and written as far as it really does protect and preserve out health, safety and welfare....enforces the liberty we RV's have.....and hopefully not not the last.

I can go on for some time with exceptions including state and local regs, and mis-interpretations.

But it is the standard to how to spec vehicle weights and what all 50 States use.

What you have to be concerned with is what is printed on your RV and inside the truck door. My Cyclone has individual axle ratings and a total trailer GVWR weight. My 2010 Ram 3500 HD has individual axle ratings and also GVWR weight. No GCWR which i think some of the newer trucks have.

This is where it begins to get complicated. There's road weight limits, and commercial weight limits that require a commercial driver's license, if your "in commerce". These are GCWR. The truck and trailer weight combined. I might be missing something, but i think these are the extent of what your truck can tow. At least on my long bed 2010 3500 HD Ram, there's no listed GCWR, but in my owner's manual, there is an estimated weight. Does that mean if i want my transmission replaced under warranty and i own up to towing a 40,000# trailer my claim will be denied........probably.

Does that mean if I'm at my manufacture's GCWR driving in the rain, at night in the hills on a two lane road with no shoulder at the posted speed limit I'm unsafe...........probably.

Does that mean i can pass commercial truckers on a long hill at 50 mph on a divided interstate highway safely when they are in low gear going 20 mph........probably.

These are all important limits and should not be exceeded at the risk of a fine and possibly inpoundment. But if you are non-commercial, and don't have to weight at truck weight stations on the interstate highways, you may never have to be concerned with a fine. But if you exceed these limits, or your tires are not properly inflated or your equipment is not well maintained, though you don't have a commercial driver's status, you have put yourself at risk as well as others and that falls within normal safe operation of a motor vehicle laws. Because you are not pulling through interstate truck weight stations, it's up to you to self enforce. And any local law enforcement or DOT can cite you in violation if it's obvious your unsafe and within their jurisdiction.

Seat time, and a trip to the scales will answer alot of your questions. It's also good to talk to professional truckers. But i don't concern myself with the actual pages of regulations, I'm way below their limits, and after 6 hours of towing with the trailer wheels within a couple of inches of the fog line, I'm ready to park it after a long day. I don't have any time constraints and I can pick my routes and if the weather is really bad out, i just pop a DVD in and wait until better weather to hit the road again.

There's also a recommended pin weight ratio for tag trailers and 5th wheel RV's. I like to put as much weight in the bed of the truck on the pin as my rated "payload" allows. I don't want to exceed my payload and let the RV control the truck, but the more weight i can put on the truck, the less likely I'll experience any rapid changes in load when i accelerate or brake or hit steep hills, the RV tracks better and the truck feels more secure with all four corners firmly planted and I'm less likely to have any fish tailing which can lead to a very bad day.
so........you also asked a very difficult question about pin weight being part of GVWR. I did a little reading, and i haven't found the exact law that say's A+B=C. I have never had that problem, I've always been way under my trailer/truck load specs.....relatively anyways. But the general consensus is that GVWR is the combination of the pin weight and the axle weights. I think the confusion is with GVW. Which is what your vehicle weights, fully loaded and driven onto the scale. GVWR, gross vehicle rating, is a legal max weight rating your vehicle can weight fully loaded and is the sum of the base curb weight, and options plus cargo. If you refer back to the sticker on the Cyclone, it gives GAWR and GVWR and also what the cargo carrying capacity is and specifically states that should never be exceeded. As far as i know, it's very difficult to have your truck or RV re-certified to a different GVWR. If you were concerned at any time about stresses put on the truck or pin box on the 5th wheel, you could always add an air suspension hitch or pin box or even change the suspension on the Cyclone. But that won't change the sticker values on the truck or RV. Or even unload the Scion and drive that until the towing gets easier.

Just a side note. it could be worse. i read about some of the smaller motor homes built on a van frame that over load with a full tank of fuel and two suit cases.



The Ram 3500 is made to tow......

2010 Ram 3500 HD
2014 Cyclone 3100
G614 Goodyears
Good Sam gps
Timark keyed alike
Xantex 2000 watt inverter "Inverter Service Center"
Blue Sea System toggle source selector
L.E.D. running lights
Quadra Bigfoot levelers
Dexter wet bolts
Boyo wireless backup camera
EMS-HW50C
TST 507RV
Smittybuilt air compressor
Splendide 2100XC
26k Husky hitch
Mor Ryde pin box
Loadlifter 5000 @40psi
6-volt 240 AH batteries
 

TedS

Well-known member
GVWR includes the pin weight. Think about it. What supports all the trailer weight? Axles and pin. The axle rating will or should exceed the GVWR. I asked Heartland how they figure GVWR. The answer was: the axle rating plus a percentage of pin weight(no commitment as to what that percentage is). FWIW.
 

scottyb

Well-known member
GVWR includes the pin weight. Think about it. What supports all the trailer weight? Axles and pin. The axle rating will or should exceed the GVWR. I asked Heartland how they figure GVWR. The answer was: the axle rating plus a percentage of pin weight(no commitment as to what that percentage is). FWIW.

Yes, but that does not apply to all of Heartlands 5th wheels. Some have a GVWR = axle rating, and some have a GVWR well above the axle rating, therefore assuming part of the GVWR is in the pin weight. Most of the Cyclone and Road Warrior 3 axles are in the 1st group.
 

TedS

Well-known member
If some gvwr's well exceed total axle ratings and the tires are matched to the axle ratings then tire failure due to overload follows.
 

danemayer

Well-known member
If some gvwr's well exceed total axle ratings and the tires are matched to the axle ratings then tire failure due to overload follows.
Here's an actual example:

GVWR = 16,000
Axle rating = 7,000 * 2= 14,000
- GVWR exceeds axle rating by 2,000
Pin weight = 3,500
Actual weight on axles when fully loaded = 12,500 / 2 = 6,250 per axle
Actual weight on each wheel = 12,500 / 4 = 3,125
Wheels and tires Load Range G - rated at 3,750

- Fully loaded to GVWR, the portion of the weight on axles does not exceed axle rating, leaving > 10% margin.
- Fully loaded to GVWR, the actual weight on wheels and tires leaves about a 20% margin relative to the tire/wheel rating.

Margin obviously would be lower with Load Range E tires rated at 3,520.
 
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