Just wanted to share the results of our trip to the scale a couple weeks ago. I took the new (to us) truck to the scale with the trailer mostly loaded, and was pleasantly surprised to see how the numbers added up. I had guessed, based on the way it 'felt' behind my half-ton that the trailer was right around 6000lbs. I was pretty doggone close!
The new truck is a 2010 F250 Crew Cab, 4x4, short bed, V-10 with the 4.10 gears
-9600lb GVWR
-23,000lb GCWR
-6000lb front GAWR
-6100lb rear GAWR
-It had one row of firewood against the cab, two bikes, a pop-up awning, and an infant swing in the bed, two cases of adult beverages in the back seat, and I was the only occupant.
The trailer is a 2004 Jayco JayFeather 29Y with a dry weight of 5100lbs and a GVWR of 6500lbs. I had the following things in/on it:
-Full water tank (empty black and gray tanks)
-No food in the fridge, pantry was stocked. The fridge is located just aft of the axles so the food placed in it will have very little affect on the tongue weight.
-No clothes
-All the bedding/pillows
-group 24 battery on tongue
-one 30lb propane tank almost empty, one full.
To start with, I hooked it up in the driveway, ball-parked the setup based on nothing more than a 'looks about right' gut feeling, then took it to a flat, almost level section of pavement at an industrial park across the freeway from the scales I planned to use. Here are the numbers I measured with a (non-certified) Stanley tape measure. I was going to use a laser transit, but my buddy was too busy to meet me.
I measured the wheel well heights on a section of flat level ground. Here are the numbers I saw as measured at the wheel well:
So, with the bars connected, I returned the front height to about where it was when unhooked, and the rear was between the connected and disconnected heights with the bars engaged. So, I knew I was in the ballpark.
So I dragged it over to the local Pilot station with a CAT scale. Here are the numbers I got:
First Pass
Conditions: WDH connected (and set based on suspension measurements).
Steer Axle: 4340lbs
Drive Axle: 4280lbs
Trailer Axle: 5560lbs
Gross Weight: 14180lbs
Second Pass
Conditions: WDH bars disconnected and stored at the very rear of the bed.
Steer Axle: 3980
Drive Axle: 4820
Trailer Axle: 5380
Gross Weight: 14180
Third pass
Conditions: Truck (as-loaded) by itself.
Steer Axle: 4300
Drive Axle: 3720
Trailer Axle: 00
Gross Weight: 8020
So, what do the numbers add up to?
The story problem: (I LOVE story problems!!!)
To determine the tongue weight of the trailer, we take the rear axle weight of the truck with the trailer connected without the bars, minus the weight of the rear axle of the truck without the trailer, minus the difference between the front axle un-hitched and hitched weight (i.e. weight that was transferred from the front axle to the rear axle by the lever action of the tongue weight).
or...
4820 - 3720 - (4300-3980)
4820 - 3720 - 320 Tongue Weight = 780lbs
Now, we add the tongue weight to the trailer axle weight to determine the gross weight of the trailer:
Gross weight = 780 + 5380 = 6160lbs
(I guessed just over 6000lbs, and I'd say that was a pretty doggone good guesstimate!! It also illustrates the weight creep phenomenon!)
Now, what is the WDH doing in terms of redistributing the tongue weight?
Well, if we look at the axle loads with and without the WDH connected, you can see that connecting the trailer without the bars adds a total of 1100lbs to the rear axle weight (4820-3720). Of that 1100lbs, 320lbs was transferred from the front axle to the rear (4300-3980). When I apply the bars, the bars lever 540lbs off the rear axle (4820-4280). It transfers 360lbs back to the front axle (4540-3980), and the balance of 180lbs to the trailer axles (5560-5380).
The short version: Applying the WDH bars puts an extra 40lbs back on the front axle over the empty weight. I could probably fine-tune it a bit by adjusting the head angle or the number of links, but I'm never going to fine tune down to 40lbs on the front axle. Close enough for me.
Conclusion: the 800lb weight bars I'm using are sized almost perfect, the setup is almost spot-on in terms of weight transfer, and the rig does, in fact, tow like a dream compared to how the half-ton did it. My only complaint is that with the truck loaded with stuff and the full water tank, the tongue rides a little lower than I'd like to see. I could adjust the shank, but I'm not sure it's worth it. The difference in the trailer front to back is only about an inch and a half, and every little bit of clearance helps the sewer plumbing and tail end clear approaches and driveways as the camper is a low-profile, lightweight unit. I think I'll leave everything where it's at for the time being.
"By George!, I think you've got it"..to my mind, you're in good shape. Thanks for posting these numbers. This is how one should hit the CAT scales. Now you know exactly where you stand. It wasn't till I took my 2500HD to the scale that I realised that it was technically too light for my 5er in the payload department and opted for a 3500. I like the safety margin & would not have known without the scale numbers.
2011 Chevy 3500 HD LTZ Duramax/Allison Crew Cab Long Box DRW
B&W Turnover Ball with Companion
Agreed. I preach the 'weigh your rig' sermon a lot around here, so I figured it was about time I verified everything for myself.
One thing I forgot to point out was that by those numbers, as scaled that day, it was at 12.6 %. I figure that the added weight for the cold goods in the fridge over the axle plus the weight of our clothes and relocation of the adult beverages to under the front bed likely kept the proportion of tongue weight at about the same percentage.
People like the OP are going to ruin this forum. Coming on here with facts is really going do discourage the "Experts" that insist on a one ton dually for that size trailer, or tell you that you need to drop three links on the bar chains, no matter what. My gosh, they can't even speculate that you have too much (or too little) tongue weight. Love those scales.
TomG2 wrote: People like the OP are going to ruin this forum. Coming on here with facts is really going do discourage the "Experts" that insist on a one ton dually for that size trailer, or tell you that you need to drop three links on the bar chains, no matter what. My gosh, they can't even speculate that you have too much (or too little) tongue weight. Love those scales.
TomG2 wrote: People like the OP are going to ruin this forum. Coming on here with facts is really going do discourage the "Experts" that insist on a one ton dually for that size trailer, or tell you that you need to drop three links on the bar chains, no matter what. My gosh, they can't even speculate that you have too much (or too little) tongue weight. Love those scales.
My humblest apologies... I don't know WHAT I was thinking!? I mean, presenting {gasp} data?? Surely I must be out of my mind.
Quick! Somebody call the weight police, STAT! I must be a wreck waiting to happen! I just don't know it yet!
Incidentally, assuming similar values for the weight distribution when connected to my half ton, I still would have been within spec. Albeit much closer to its 7300 lb rating, but within the spec none the less.
I want to get the new tv dialed in, got lucky, and found a CAT scale less than 2 miles from my house. I've got the "baseline" (unladen) axle weights and ride heights. Now to hook up, measure, and weigh the HTT with and w/o the WD bars and see if the weight transfer is right and get the trailer level.
I've been crunching the numbers & didn't realize the GVWR (7200#) was less than the sum of the front & rear axles (7600#.) And I'll run out of GCWR (15400#) before I hit the published max trailer tow figure (9700#.) But since the HTT will probably come in at 5,000# or less I should be well under the limits.
If you get re-weighted within 24 hours I was told you don't pay for the 2nd weigh-in. So I'll be able to get the "with" and "w/o" WD bar weights for one fee.
2013 North Trail 21FBS
2012 F-150 XLT Ecoboost ("EcoBeast") scab
Congratulations on a excellent set of scales data and an excellent analysis and presentation of results. It's great to see such good agreement between data and theory.
It's also very informative to compare your wheel well heights with the scales data. In this case, the comparison indicates the heights can be misleading.
For example:
The tongue weight (with no WD applied) caused the front to rise 0.25". The tongue weight (with no WD applied) caused the front axle load to decrease 320#.
This indicates a front-axle spring constant of 320/0.25 = 1280#/inch.
Application of WD caused the front to drop 0.5". Application of WD caused 360# to be added back onto the front axle.
This indicates a front-axle spring constant of 360/0.5 = 720#/inch.
The indicated constants should be approximately the same. An initial front-end rise of about 1/2" would give better agreement.
The tongue weight (with no WD applied) caused the rear to drop 1.375". The tongue weight (with no WD applied) caused the rear axle load to increase 1100#.
This indicates a rear-axle spring constant of 1100/1.375 = 800#.
Application of WD caused the rear to rise 0.25". Application of WD caused 540# to be removed from the rear axle.
This indicates a rear-axle spring constant of 540/0.25 = 2160#/inch.
Again the spring constants should be equal.
A rear-end rise (due to WD application) of about 5/8" would give better agreement.
As always, wheel well heights should be considered as only a approximate indication of axle weight and load transfer.
Properly-obtained scales data will provide more accurate information.
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