Formula for determing loaded tongue weights?

[TCNashville]

I've been reading a lot of posts about campers with heavy tongues being towed with marginal tow vehicles. I think if people knew how to load their campers in this situation, it might make for safer travel. I was once told that if you measure the distance from the axle to the hitch, then divide that number by 2, everything on the hitch side of the line was considered extra tongue weight. Add in the actual WD hitch weight and whats in the TV, you should have a pretty good estimate. Is this a good assessment? When I bought my 2012 Eagle, I weighed everything that went in on a bathroom scale to give me a rough estimate on my loaded weight. The weight of my trailer in the brochure was 8100#. When I picked up the trailer, the yellow sticker read 8600# from the factory. I was wondering why there was that much discrepancy and why they don't give factory tongue weights as well.

[Grumpy]

You can do it with a bathroom scale, use a 4x4 instead of a 2x4


http://http://www.etrailer.com/mm5/g.../faq118_dd.jpg

[Rustic Eagle]

Originally Posted by TCNASHVILLE

I've been reading a lot of posts about campers with heavy tongues being towed with marginal tow vehicles. I think if people knew how to load their campers in this situation, it might make for safer travel.......snip

I couldn't agree more.., but few folks take the time to visit their local CAT Scale which is the only way to take the guess work out of the equation. CAT scale how to: http://www.jaycoowners.com/showthrea...igh-Your-tt-tv

Originally Posted by TCNASHVILLE

snip.......I was once told that if you measure the distance from the axle to the hitch, then divide that number by 2, everything on the hitch side of the line was considered extra tongue weight. Add in the actual WD hitch weight and whats in the TV, you should have a pretty good estimate. Is this a good assessment? ......snip

I may not be interpreting your statement correctly....., but if your referring to the added cargo within the TV but placed to rear of the TV's rear axle, I don't know if I would refer to it as being "considered extra tongue weight". The actual loaded TT tongue weight once placed on the hitch ball remains the same (is what it is), and in turn has an effect of the weight placed over the TV's rear axle, as does the added cargo placed to the rear of the TV's rear axle.

BUT......., because of the physics behind the function of a WDH it has been shown that the WDH supports not just the weight of the loaded TT tongue weight but also a "percentage" of the added cargo weight to the rear of the TV's rear axle.

If one doesn't have the TT in their possession, then we are left with making assumptions using the 10% to 15% manufacturer's recommendation to identify a loaded tongue weight range. Once a TV/TT combination is in hand, either a CAT scale or the use of a Sherline Trailer Tongue Scale is the best way to confirm one's actual tongue weight.

I use my Sherline often in helping others: http://www.sherline.com/lm.htm

Originally Posted by TCNASHVILLE

snip.....When I bought my 2012 Eagle, I weighed everything that went in on a bathroom scale to give me a rough estimate on my loaded weight. The weight of my trailer in the brochure was 8100#. When I picked up the trailer, the yellow sticker read 8600# from the factory. I was wondering why there was that much discrepancy and why they don't give factory tongue weights as well.

This is where many folks can get miss lead when speaking to RV sales personnel. The published (brochures, web sites, etc.) UVW of a particular FW/TT/HTT, etc., represents the base model unit at a specific location within the manufactures assembly process. Outside supplied products such as A/C's, awnings, specific appliances, LP liquid, etc., may not be included in a UVW value. Since all manufactures have there own way of establishing a UVW value, one must be very careful (or ignore) in using these weights.

The "Yellow Sticker": Because of the issues associated with UVW's, the government starting in 2010 initiated a new industry wide regulation that all RV manufactures must attach a "Ship Weight" (weight as it departs the factory) sticker to the RV that also reflects the actual CCC which in most cases is lower then the published value.

This new regulation also requires RV dealerships to attached a revised sticker to the new RV if they add more then 100lbs to the unit thus reflecting the decrease in the Yellow Sticker CCC value.

Hope this sheds a little light on your questions.

Bob

[TCNashville]

Thanks again Bob for you are a wealth of knowledge. I guess the point I was trying to make is that even the best WDH can't compensate for overloading or lack of towing ability. I think a lot of people think if they can tow it, they're ok. A person with a 1/2 ton pickup may be able to tow 10,000#'s, but if the tongue weight exceeds the maximum of the vehicle, a dangerous situation presents itself and no WDH will make up for that unless special modifications are made to the suspension. Wouldn't it be nice if RV dealerships had CAT scales to ensure proper setup? They may not sell as many trailers though.

[Rustic Eagle]

Originally Posted by TCNASHVILLE

snip...... is that even the best WDH can't compensate for overloading or lack of towing ability.....snip

I couldn't agree more!

[RoyBraddy]

these guys are pretty handy to have around too but are alittle on the expensive side. My neighbor who everyone here in the neighborhood calls "Gary the tool man" has one that I can borrow every now and then.

Load Master Scale, Hydraulic Pressure Gauge for Tongue Weights, 0 to 2,000 Lbs
This one shown goes for $175


sample photo from GOOGLE images

Roy Ken

[E&J push'n wind]

Originally Posted by TCNASHVILLE

Thanks again Bob for you are a wealth of knowledge. I guess the point I was trying to make is that even the best WDH can't compensate for overloading or lack of towing ability. I think a lot of people think if they can tow it, they're ok. A person with a 1/2 ton pickup may be able to tow 10,000#'s, but if the tongue weight exceeds the maximum of the vehicle, a dangerous situation presents itself and no WDH will make up for that unless special modifications are made to the suspension. Wouldn't it be nice if RV dealerships had CAT scales to ensure proper setup? They may not sell as many trailers though.

I understand the point of this statement however I disagree with it up to a point. A lot of times a MFG. will state a GVWR, GAWR fr/rr and GCWR for a certain year model. In subsequent years without changing ANYTHING to the vehicle except perhaps the grill, these "ratings" will increase and by a sizeable amount sometimes. So the guy who bought the older vehicle is overloaded and "dangerous" in the year he bought the vehicle because of his TT but as the "same vehicle" became newer with only a grill change he is no longer over loaded. In the same manner, this can change the other way. Toyota for example de-rated the tow rating of their 1/2 ton pick up and SUV. So what's the guy to do that has one of the older Toyota's. Is he now dangerous because the MFG. in later years reeled in what the vehicles are able to tow?

It is not always so cut and dry, I'm not advocating anybody overload their vehicle but many times a little discretion goes a long way. The question I supose is knowing what is and is not overloading your TV? My TV for example has GAWR's of 4300 lbs. rr and 3700 lbs. fr with a GVWR of 7300 lbs. My TV is overloaded way before the axles according to the MFG. Where did the other 700 lbs. go and why is it not useable, or is it? Am I unsafe if I go over the 7300 lbs. but stay within the 8K combined wt. of the axles without exceeding the rating of either? Is this the margin that MFG's use when they want to increase the tow rating of a vehicle without changing a single thing in drive line, suspension or braking?

I hope I didn't ruffle any feathers, currious as to what others have to say concerning this.

[Rustic Eagle]

Originally Posted by E&J push'n wind

snip.......My TV for example has GAWR's of 4300 lbs. rr and 3700 lbs. fr with a GVWR of 7300 lbs. My TV is overloaded way before the axles according to the MFG. Where did the other 700 lbs. go and why is it not useable, or is it? Am I unsafe if I go over the 7300 lbs. but stay within the 8K combined wt. of the axles without exceeding the rating of either?...... snip

I look at a TV axle as an individual component having it's own specified weight limit.., and don't believe the combined weight of both F/R axle weight limits takes into consideration other TV components included in the GVWR (ie; frame, drivetrain, brakes, etc.). Would you be "unsafe" if you went over your TV's 7,300lb GVWR, I guess it's possible...., but premature component wear could be a real issue.

You bring up some interesting points in your post that merit further discussion/detail, but I don't want to steer to far off the OP's subject matter.

Bob

[Denise]

Don't know if this helps, but...

When we bought our tt in 2009, and as amateurs we really needed to know if our loaded tongue was ultimately not safe but there weren't any CAT scales available. We had an idea our dealer didn't intstall the wdh correctly (they installed the one we didn't pay for either!) but as amatures only really had a clearer idea once we did a certain "measurement". I wish I had access to my notes (they're in the tt I think), but a member from another rv forum had us park our truck on level ground and measure
-the distance from the wheel well to the ground on both the front and rear wheels. I think we also measured the rear bumper to the ground (?)... I can't remember.

Anyhow, the idea was then to hookup the tt, and re-measure
-without the wdh (the front of the truck would go up while the rear goes down)
-then hookup the wdh and take final measurements (the front of the truck should be back down close to where it was before being hitched)

I think the formula was something like the front of the truck shouldn't be more than an inch up after hooking up the wdh, or the tongue weight is too heavy. It wasn't exact science, but it definitely confirmed that the techs screwed up. They also put on the wrong hitch. The dealer wound up installing our current wdh (correctly I might add), and we were good to go.

Does anyone know what formula I'm referring to? If so, maybe you can post the actual info for the formula

[Rustic Eagle]

Originally Posted by healthi

snip...... Does anyone know what formula I'm referring to? If so, maybe you can post the actual info for the formula

healthi,

The process that you described is the adjustment procedure that comes with about every standard WDH. Although it doesn't tell one what the loaded tongue weight value is, it does through the process of F/R TV wheel well measurements insure that the proper weight has been returned (ball park) to the TV's front suspension. The effect of the tongue weight being placed on the hitch ball removes weight from the TV's front suspension and increases the load over the TV's rear axle. The F/R wheel well measurements are taken prior to hitching, and after hitching once the WDH spring bars are engaged.

The three most common ways of determining tongue weight are a CAT scale, Sherline tongue scale, and a bathroom scale (additional material/set-up required).

Bob

[OnTheGo]

Roy,

That seems like a good way to go. I'm going to see if I can rent one.

Originally Posted by RoyBraddy

these guys are pretty handy to have around too but are alittle on the expensive side. My neighbor who everyone here in the neighborhood calls "Gary the tool man" has one that I can borrow every now and then.

Load Master Scale, Hydraulic Pressure Gauge for Tongue Weights, 0 to 2,000 Lbs
This one shown goes for $175

Attachment 6243
sample photo from GOOGLE images

Roy Ken

[Denise]

Roy, If you find a way to rent one, post in this thread the resources you find.... it could help someone reading this down the road who doesn't feel like making their own, and/or don't have a larger commercial scale to go to

[Rustic Eagle]

The Sherline LM2000 trailer tongue weight scale that I 'linked' in my earler post is on sale at e-trailer for $123.95:



http://www.etrailer.com/Tools/Sherline/5780.html

Bob