Chuck&Gail
In the Colorado Mountains
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Remember hitch weight target is 13% of fully loaded TT weight. When in doubt use 13% of TT GVWR. So you need a TT with GVWR of under about 6000# as above.
Chuck
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LarryJM
NoVa
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Joined: 11/09/2007
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Chuck&Gail wrote:Remember hitch weight target is 13% of fully loaded TT weight. When in doubt use 13% of TT GVWR. So you need a TT with GVWR of under about 6000# as above.
IMHO that's great advice, but when trying to get what you want with an existing TV is where folks desires overshadow what they can realistically and safety do.
Larry
2001 standard box 7.3L E-350 PSD Van with 4.10 rear and 2007 Holiday Rambler Aluma-Lite 8306S Been RV'ing since 1974. TRAILER MODS
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Ron Gratz
full time RVer
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Joined: 12/27/2003
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Quote:Remember hitch weight target is 13% of fully loaded TT weight. When in doubt use 13% of TT GVWR. So you need a TT with GVWR of under about 6000# as above.
Just to avoid confusion -- GVW is not the same as GVWR.
The actual "loaded TT weight" is the GVW of the TT. If you want 13% tongue weight, you must base the tongue weight on the GVW and not on the GVWR.
If, for example, your calculations say the TT's GVW should not exceed 6,500#, there is nothing wrong with having a TT which has a GVWR of 7,000# or 8,000# or more. Just keep the loaded weight to 6,500# or less.
Ron
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Pleco
NY state
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Joined: 08/26/2008
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SemperFiCop wrote:Your Max hitch weight is 860 pounds, with HD Tow Package (Class IV Hitch)
the sticker is located under the rear bumper cover
(unless it was removed or the sticker fell off)
Woohoo, thx for that tip! I just checked for the sticker, and now I know for sure what the limits are on the hitch. It says
....................tongue.....TT
with WD hitch....895......8950
without WD.......600......6000
It then warns that this is the limit of the hitch itself, and not necessarily what the whole vehicle can tow.
In the interest of stability, I would like my tongue weight to be in the 13-15% range, so that would give me a max TT total gross weight of about 6900 pounds. If I am now considering sub 5500# TT models, I think I'll be under 6900 by a few hundred pounds. If my TT comes in at 6400 pounds fully loaded, an 895 tongue weight would be 14%. I think that would be a great goal for me. Any opinions? Should I shoot for a lower tongue weight of say 800-850 for the loaded trailer, just to leave some elbow room?
Thx so much for all the great input!
PS: I must say, I find it very strange that the hitch sticker states different tongue weight capacities with and without a WD hitch, when the sticky here clear states that a WD hitch has no affect on actual tongue weight. I am not saying the experts here are wrong, but that I just find it strange.
* This post was
edited 08/31/08 06:20pm by Pleco *
'06 Expedition 5.4L, 4x4, towing package, 119 wheelbase, 3.73 gears
GVWR-7300, GCWR-14500, Max tow-8600, GAWR front-3275,
GAWR rear-4128, Tire load rating-2535, Weighs 5980 with me and a full tank of gas.
Still searching for the right travel trailer...
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BarneyS
S.E. Lower Michigan
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Pleco wrote:PS: I must say, I find it very strange that the hitch sticker states different tongue weight capacities with and without a WD hitch, when the sticky here clear states that a WD hitch has no affect on actual tongue weight. I am not saying the experts here are wrong, but that I just find it strange.
Not strange at all! You are confusing actual tongue weight with the weight placed on the receiver of the truck. The only way to change the actual tongue weight of a trailer is 1. to load stuff in front of or behind the axles, 2. move the axles themselves, or 3. make the tongue longer.
The weight placed on the receiver of the truck can be changed by adjusting the WD bars. This removes some of the weight as explained in that sticky and moves it forward and backward to the truck front axle and the trailer rear axles.
Compare it with a wheelbarrow. The wheelbarrow contains a load of sand (tongue weight) and the bed of the wheelbarrow is the tongue/hitch of the trailer. The handles of the wheelbarrow are the WD bars and your arms are the chains that lift them. The front wheel is the front axle of the truck. The rear supports are the rear axle of the truck and your two feet are the trailer axles. When you lift up on the handles (bars & chains), you transfer the force (weight of sand) from the rear supports (rear axle of truck) to the front wheel (front axle of truck), but at the same time the lifting force of your arms (chains) increases the load on your feet (axles of trailer).
At no time during this whole operation did the load in the wheelbarrow change. It is still the same weight of sand (tonge weight) that you started with. The forces that that load of sand created in the wheelbarrow has been moved around but the weight is still the same.
The same thing happens with the tongue weight of the travel trailer when you use WD. The actual tongue weight does not change, only the forces that it creates is moved around.
Now, does that sticky make better sense to you?
Barney
2004 Sunnybrook 30FKS TT
Hensley "Arrow" 1400# hitch
2002 Ford F250 Super Duty, 7.3L PSD
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Ron Gratz
full time RVer
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Joined: 12/27/2003
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Pleco wrote:....................tongue.....TT
with WD hitch....895......8950
without WD.......600......6000
PS: I must say, I find it very strange that the hitch sticker states different tongue weight capacities with and without a WD hitch, when the sticky here clear states that a WD hitch has no affect on actual tongue weight. I am not saying the experts here are wrong, but that I just find it strange.
Without WD, a tongue weight of 600# would produce a vertical load of about 600# on the receiver.
With a properly sized and adjusted WD system, a tongue weight of 895# might produce a vertical load of about 650# on the receiver.
Vertical load on receiver = tongue weight - load transferred to TT axles by WD system.
The tongue weight does not change. The vertical load on the receiver does.
Ron
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Pleco
NY state
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The example clears it up a little for me, but this last paragraph from the initial post in the sticky still seems contradictory in my limited understanding:
Quote:It is interesting to note that TT weight and “tongue weight” do not enter into these calculations. The WD hitch does not distribute “tongue weight”. It simply removes load from the TV’s rear axle and distributes it to the TV’s front axle and the TT’s axles.
However, I read the whole sticky again, and I think I am understanding. The sticky makes a distinction between the "vertical load on the receiver" and the tongue weight. The example given shows a 300 pound reduction on "vertical load on the receiver"
So, I guess the sticker on my TV is assuming a WD hitch is gonna take 895-600=295# off the "vertical load on the receiver". However, it seems like the exact load recduction depends on adjusting the WD hitch correctly, as well as TV wheelbase, rear overhang, and TT axle to tongue distance.
Do you guys recommend I stay a little under the recommended max, like say 850 for example - just to be safe? Also, how much do you suppose the battery, propane, and hitch itself will add to the dry hitch weight of a trailer? 200#? If it adds too much, how much might I realistically expect to offset by loading more cargo in the rear of the TT?
Thx again for the advice!
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Golden_HVAC
Fulltime, CA, USA
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Joined: 08/19/2003
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Hi,
If you put 850 pounds on your hitch, before you hook up the WD bars, you will push down on the hitch ball with 850 pounds. This ball is about 50" behind the rear axle and lets just say (for simple math) that your wheelbase is only 100". You would force down the hitch ball with 850 pounds and this will cause the pivot (the rear axle) to go down, raising up the front of the truck frame, taking 425 pounds off the front axle. Thus it will load up the rear axle with 1,275 additional pounds.
The hitch is not rated for that much weight, and you would probably overload the rear axle in the process, as well as both rear tires. But that is what will happen before the WD bars are attached and tightened up.
When you tighten the hitch, then you take about 200 pounds off the rear axle and place it back on the front axle. Now comes more math. If it is 100" from the trailer hitch ball to the forward trailer axle, then 200 pounds would also be transferred to the trailer axle. However I would expect the front trailer axle to be 200" or farther behind the ball - so only about 100 pounds is transferred to the trailer axle in your case. 200" = 16'8".
One thing that will spoil your whole plan that has not been mentioned yet is the 100 pound box that the Hensley hitch will arrive in. Yes this will be added to the hitch on the Expidition, and needs to be added to the tounge weight of the trailer to get your total hitch weight. (it might even be a 120 pound hitch? I have not checked the weight on one.)
You will still have 850 pounds of hitch weight pushing down on your 100 pound hitch, and then the spring bars will attempt to move away 200 pounds forward and 100 pounds rearward when they get tight. Because of the way the spring bars work, the hitch ball will actually see something like 1,150 pounds on it, but not to worry, it is designed for that.
Also before you order anything, see if the trailer uses a 2" or 2-5/16" diameter hitch ball. Usually the 2" is limited to only 7,000 pounds, while the larger is limited to 12,000 pounds or more, depending on it's construction.
It is also recomended that a dab of greese be put on the hitch ball, so that it will be lubricated while towing.
I like the compairison to a wheelbarrow, where when you pick up the handles, you put weight on your arms, just like the trailer axle will get some weight when the chains are tightened.
Fred.
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eddeeeee
colorado
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Joined: 04/16/2006
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Don't forget that a Hensley arrow will add almost 200# of weight to the tongue weight. It is worth it, however.
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Ron Gratz
full time RVer
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Joined: 12/27/2003
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My numerical calculations differ from Fred's, but I think our general conclusions are similar. Using some dimensions which are a little more representative of your TV and potential TT, assume:
TV wheelbase = 120"
TV ball overhang = 60"
TT ball to axles' center distance = 180"
If you place an 850# load on the ball without applying WD,
TV's front axle load will decrease by 425#
TV's rear axle load will increase by 1,275#
Vertical load on receiver will be 850#
If you then load the WD bars so that 200# is transferred to the TT axles, the WD system will cause
TV's front axle load to increase by 400#
TV's rear axle load to decrease by 600#
The net theoretical result, relative to "unhitched" loads, due to tongue weight plus weight distribution gives:
TV's front axle load decreases by 25#
TV's rear axle load increases by 675#
TT's axle load increases by 200#
Vertical load on receiver will be 650#
If the above values are reasonable estimates and if you know what the "unhitched" axle loads are likely to be, then you should have a good idea where you will stand relative to GAWRs, GVWRs, GCWR, and receiver rating.
Ron
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