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-   -   Tongue weight verses tongue height - level the WD hitch? (http://www.airforums.com/forums/f464/tongue-weight-verses-tongue-height-level-the-wd-hitch-37697.html)

HowieE 11-17-2007 11:08 AM

Tongue weight verses tongue height - level the WD hitch?
 
Originaly I had posted a question about towing a 34fter with an Excursion. My question arose from the significant amount of sway I experienced the first time we towed. In responce I got many replies regarding the shortcomes of the Excursion suspension. I also got several responces from individuals claiming they are not having any problems. I am now looking at the problem from a different angle.

Given that the 34 has 3 axles and that the Airstream suspension does not equalize the load between the axles when the frame is not parallel to the road I am considering the effect that the tongue height has on the tongue weight. The trailer was riding dead level and only placing 540 lbs on the truck rear axle Given that the WD hitch is set up to transfer weight to the front axle it appear likely that if I raise the hitch a bit, thus removing some weight of the trailer's front axle it should increase the tongue weight to come closer to the recomended 10- 12% of trailer weight.

My question to those of you towing 34s is how close to level is your trailer when hitched up? Is it dead level, tongue high, or tongue low?

jimmickle 11-17-2007 11:21 AM

If your tongue weight is only just over 500 lbs, you need to shift things in the trailer to get to 12%. With tongue weight under 10%, it will never be stable, no matter what you do. I would think that you should be about 1000#.

thecatsandi 11-17-2007 11:24 AM

Too Little weight?
 
Quote:

Originally Posted by HowieE
The trailer was riding dead level and only placing 540 lbs on the truck rear axle Given that the WD hitch is set up to transfer weight to the front axle it appear likely that if I raise the hitch a bit, thus removing some weight of the trailer's front axle it should increase the tongue weight to come closer to the recomended 10- 12% of trailer weight.

Howie,
It seems you already figured out there is too little weight on the tongue. Was this before or after the WD was hooked up? Given the weight of the trailer it should be around 1000 lbs before the WD is hooked up.
Have you loked at the loading of your trailer? You may have too much stuff stashed in the rear.

Inland RV Center, In 11-17-2007 12:04 PM

Quote:

Originally Posted by HowieE
Originaly I had posted a question about towing a 34fter with an Excursion. My question arose from the significant amount of sway I experienced the first time we towed. In responce I got many replies regarding the shortcomes of the Excursion suspension. I also got several responces from individuals claiming they are not having any problems. I am now looking at the problem from a different angle.

Given that the 34 has 3 axles and that the Airstream suspension does not equalize the load between the axles when the frame is not parallel to the road I am considering the effect that the tongue height has on the tongue weight. The trailer was riding dead level and only placing 540 lbs on the truck rear axle Given that the WD hitch is set up to transfer weight to the front axle it appear likely that if I raise the hitch a bit, thus removing some weight of the trailer's front axle it should increase the tongue weight to come closer to the recomended 10- 12% of trailer weight.

My question to those of you towing 34s is how close to level is your trailer when hitched up? Is it dead level, tongue high, or tongue low?


You state that you have new 3200 pound axles.

Unfortunately, they should be 4000 pounds each.

At 3200 punds, they won't last very long, since they are overloaded, with little to no reserve.

Andy

HowieE 11-17-2007 12:04 PM

Quote:

Originally Posted by thecatsandi
Howie,
Given the weight of the trailer it should be around 1000 lbs before the WD is hooked up.
Have you loked at the loading of your trailer? You may have too much stuff stashed in the rear.

The weight was after hitching. My problem now is the trailer is empty for winter storage so any weight I take now are questionable.

The reason I am questioning the tongue height is I that it and the truck are the only difference from when I was towing with my Burb. The traile rloading was the same. I am not ready to accept that the Excursion is that poorly designed. Tongue height should have the effect of weight transfer. Problem is I can't remember how close to dead level the trailer was when hitched to the Burg.

Maybe I have to move the fossil collection forward.

HowieE 11-17-2007 12:06 PM

Gee Andy you sold me the axles.

azflycaster 11-17-2007 12:13 PM

The chart shows that your trailer is around 7000 pounds dry + options and the hitch wt should be 800 pounds. Is the 500+ at the rear axels with the WD hitch setup?

HowieE 11-17-2007 12:19 PM

Quote:

Originally Posted by azflycaster
The chart shows that your trailer is around 7000 pounds dry + options and the hitch wt should be 800 pounds. Is the 500+ at the rear axels with the WD hitch setup?

Yes
As originaly set up the I had added 540 lbs to the rear axle and 40 lbs to the front axle. I then kicked the hitch head back one notch to add a little more to the front axle, checking difference by ruler measurements only. I have not returned to the scales with this set up. However the sway problem may even be worse with this setting. Assuming the real axle is now seeing even less weight.

jimmickle 11-17-2007 12:55 PM

What kind of tires on the excursion? If they are P rated, that is probably your problem. P tires are just too soft. LT tires may solve your problem, it sure did in my Jeep Grand Cherokee towing a 25SS. A friend had a similar stability problem on a 1/2 ton burb. It came with P even with a trailer package. LT tires also solved his problem.

Jim

2airishuman 11-17-2007 01:03 PM

Quote:

Originally Posted by Inland RV Center, In
You state that you have new 3200 pound axles.Unfortunately, they should be 4000 pounds each....At 3200 punds, they won't last very long...

well even the NEW triples don't come equipped with 4k axles...

hi jim!

how are ya?

he's got new E rated tires on the beast...

http://www.airforums.com/forums/f238...ion-36898.html

Quote:

Originally Posted by HowieE
Originaly I had posted a question about towing a 34fter with an Excursion. My question arose from the significant amount of sway I experienced the first time we towed....

and as i recall this first trip was with the exc' tires at 50-55 psi?

no offense howieE, but...

have you tired ADDING AIR TO THE EXCURSION TIRES YET?

it's great you haven't given up on the exc', but why in the world don't you at least try proper inflation pressures...

at ~65-70 psi +/- a lbs or 2 your towing experience will GREATLY improve.

and the advise about suspension upgrades is rock solid.

clearly having the tongue mass at 10-15 % is important...

and that % IS measured WITH THE TRAILER LEVEL...

raising or lowering tongue with a different drop bar isn't how to arrive at proper tongue mass...

clearly IF the tongue is too LOW or too HIGH the triple axle is made more like a single or double axle unit...

with one axle overloaded.

why would you be trying 2 intentionally overload any one axle, when level is the preferred orientation?

try adding air to the tv tires as virtually everyone else with E rated tires has done on the fords?

we've covered this issue in other threads and with other owners who had issues until the tv tires were PROPERLY inflated...

start here with post # 40 or so....

http://www.airforums.com/forums/f464...ing-23754.html

or read here where tires pressures were ignored while fiddling with the hitch...

http://www.airforums.com/forums/f437/ooops-23162.html

cheers
2air'

i try to tow the 34 dead level, but have had the trailer 1 inch high AND one inch low at the tongue on some trips....

towing was basically the same in both positions over 1000s of miles, with a little difference is tires temps and wear...

the 540 lbs on your rear truck axle ISN'T the tongue weight. that is the tv rear axle load AFTER w/d is adjusted...

you will need to weigh the tongue un hitched and LEVEL to determine tongue mass and adjust % of total trailer weight....

adjusting the spring bars alters the re-distribution, BUT it does NOT change the actual tongue mass.

Tarheel 11-17-2007 01:17 PM

Howie my 34' 94 limited was light on the tongue right at 700 lbs. If the potable water tank was not filled then it became a problem. There is a kit from Airstream that adds steel flatbar inside the frame in the hitch area to increase weight, I was satisfied by adding lead shot bags inside the horizontal bottle area. With the water tank filled and the addition of the shot bags I had no issues. This trailer has been well over 150 k miles and has never been in an accident. My new 34' has 1250 lbs on the tongue so this is no longer an issue. Best of luck. Rick

HowieE 11-17-2007 01:52 PM

2airishuman

No offence but the tires are inflated to the recomended tire pressure as per the manufacture, the same pressure I towed this trailer with for the last 12 years. I have had several conversations with Michelin engineers on this subject to conferm the pressures against the axle weights.

The height of the hitch has no effect on the WD aspects of the hitch. The hitch WD effect is a function of the head angle. Heights are suggested to have the trailer ride level. My thoughts behind changing the hitch height slightly was to experiment with weight changes to the TV short of adding weights or moving stuff around.

As for the axle rating. The trailer original came with 2800 lb axles. I increased them to 3200 because 2800 was just at the limit and they had sagged. That was 2 years ago and had no effect on the overall towing while towing with the Burb.

Quote:

Originally Posted by Tarheel
Howie my 34' 94 limited was light on the tongue right at 700 lbs. If the potable water tank was not filled then it became a problem. There is a kit from Airstream that adds steel flatbar inside the frame in the hitch area to increase weight, I was satisfied by adding lead shot bags inside the horizontal bottle area. With the water tank filled and the addition of the shot bags I had no issues. This trailer has been well over 150 k miles and has never been in an accident. My new 34' has 1250 lbs on the tongue so this is no longer an issue. Best of luck. Rick

Interesting comments. In both case of towing with the Excursion I was running with empty Gas bottles and very light on fresh water. I generaly have a 1/4 tank of fresh water on and it is between the front 2 axles. My local Cat Scale has a rule against dropping the trailer on the scale so I am going to have to set up a bean system and use a bathroom scale to confirm the tongue weight.

2airishuman 11-17-2007 02:02 PM

well i'm not sure that the tire pressures used for the tow vehicle over the last 12 years matter much...

with a DIFFERENT tow vehicle and new tires.

i've read the comments attributed to the mich' guy and they really seem to conflict with everthing else i've read about E rated tires.

you seem willing to 'experiment' with lots of the other settings and parameters,

except the tire pressures...

here's a wild guess and if it's incorrect so be it....

you believe that adding air ( within the maker's inflation limits ) will reduce the effective 'grip' of the tires?

is that close?

and hey how did your front end repairs turn out, i was hoping for an update and photos!

cheers
2air'


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