Owners Manual Warning - Stiff T.V. Springs

[dkottum]

My 2007 Safari Owners Manual has a note and warning at end of page B-1.

NOTE: Be realistic when ordering heavy duty springs. Only springs heavy enough to support your loaded vehicle (not including trailer) are necessary. Too harsh of spring rate will only shorten the life of the tow vehicle and trailer, and make your journeys less enjoyable.

! WARNING: Too stiff of springs can hinder the action of the weight equalizing hitch and prevent the transfer of weight to the front of the vehicle.

What is the meaning of these statements?

[Road Ruler]

A vehicle's suspension system is designed for many reasons.

It helps keep all 4 wheels on the road
Absorbs bumps and road irregularities which add to passenger comfort and vehicle control.
Reduces wear and tear on the vehicles structure and components

If the suspension is over built and unnecessarily stiff or firm it will reduce all or many of the above mentioned benefits.

The overly firm suspension can also hinder the positive effects and reduce the action of the WDH by restricting movement and or adding stress to the trailer frame and structure.

[ROBERT CROSS]

Originally Posted by dkottum

What is the meaning of these statements?

Excessive spring rates cause damage, don't go overboard.

Listen to what others have been saying here for years.

Match your hitch, TV and trailer.

[dwightdi]

Your Airstream has soft springs in it for a soft ride that absorbs the road shocks and does not transmit them to the body of the trailer or the contents. if you mount it to a stiffly sprung TV that will in effect increase the stiffness of the trailer's suspension when using fairly stiff Weight distribution bars and cause more road shock to be transmitted to the trailer body and its contents. You still need to have suspension stiff enough that it does not bottom out when it comes in contact with the average roughness. If it bottoms out the whole suspension becomes rigid and all the effect is lost. The suspension also needs to be stiff enough that the steering geometry remains constant and the truck does not wallow when trying to steer around things or make lane changes.

[jmtandem]

Spend a quality evening reading all the commentary about too much truck, too strong weight distribution springs, etc. and how it affects (damages) the Airstream trailers. This topic can keep you reading far into the night.

[dkottum]

The first "NOTE" seems fairly straightforward to me, do not get heavier springs or truck than you need, or your will damage your t.v., trailer, and have an uncomfortable ride.

The second "! WARNING" is less clear. To me, it suggests that too stiff of springs hinders transfer of tongue weight to the front axle. Does that mean most of the tongue weight is split between the rear axle and the trailer axle(s) on the too-heavily sprung tv, and only with additional tightening can weight be restored to the front axle? This further suggests that a heavily-sprung tv would have a more rigid connection at the hitch, than a tv more closely matched to the tongue weight of the trailer.

Oh boy, this has been argued here once or twice, with no resolution. But that is NOT what I am looking for. I am ONLY looking for an understanding of my Owners Manual.

The inventors gave us the Hensley; now if they could only get rid of those d@#% weight distribution bars.

[Ag&Au]

Originally Posted by dkottum

............................................

The second "! WARNING" is less clear. To me, it suggests that too stiff of springs hinders transfer of tongue weight to the front axle. Does that mean most of the tongue weight is split between the rear axle and the trailer axle(s) on the too-heavily sprung tv, and only with additional tightening can weight be restored to the front axle? This further suggests that a heavily-sprung tv would have a more rigid connection at the hitch, than a tv more closely matched to the tongue weight of the trailer.

Oh boy, this has been argued here once or twice, with no resolution. But that is NOT what I am looking for. I am ONLY looking for an understanding of my Owners Manual.

The inventors gave us the Hensley; now if they could only get rid of those d@#% weight distribution bars.

I just drew a diagram using the ultimate stiff suspension. ( axles bolted to frame). After messing with that with what I learned about statics in physics, I am sure that second statement is not true as they wrote it.
I don't know what they are thinking, but I am thinking there is some fuzzy logic involved. They also lost some credibility with me by saying "too stiff of springs" instead of "springs too stiff" or " too stiff springs"
Regards,
Ken

[Road Ruler]

Another part of the physics is that it takes more effort to transfer weight on vehicles with a long wheel base compared to shorter wheel based vehicles.

Longer wheel based vehicles tend to need heavier bars to get the appropriate weight transfer.

[mwells4654]

I get more confused every time this subject comes up - I was happy with my TV-WDH-TT setup until I did some reading here. I still do not know if I need lighter weight bars or not. Equalizer says probably not - some say yes - Equalizer says their new e2 is different than other hitches. I can order 800 lb. bars but do I really need the expense - it has 1000 lb bars. I am only pulling a 71 overlander international with a 2006 GMC Sierra 4 door pickup with trailer towing package. I know I need new axles (which I will do in a couple months). But, now - do I or do I not need 800 lb. bars?

[TomW]

Originally Posted by dkottum

My 2007 Safari Owners Manual has a note and warning at end of page B-1... [good stuff]...
What is the meaning of these statements?

For what it's worth, this is the first time I have heard that Airstream owner's manuals now address this particular issue. Cool.

This particular thread starts out kinda slow as far as looking like it pertains to what you asked about. But, should you care to read & think about all of it, you will gain a deeper understanding about what your owner's manual is referencing.

Changes were made to my setup based on what I read.

Tom

[ROBERT CROSS]

DK....here is a pretty good read on wd hitches.

I really don't believe that a modern 3/4 suspension will be to stiff if set up properly with the correct hitch and wd bars. At least not GM anyway JMO

[safari 28]

Do I hear, all of us really only need a well equipped 1/2 ton gasser for ANYTHING EVER MADE BY AIRSTREAM? I suspect the mother ship is tired of repairs due to 3/4 ton diesels that are not needed and making warranty issues already a problem worse. At some point it must be surfacing what Inland Andy has been saying all along. Over rigged equals repairs. At best, removal of the springs and full air ride must be the choice if you want the so called "relaxed towing" of a diesel.

[FlashSilver]

Originally Posted by w7ts

IThey also lost some credibility with me by saying "too stiff of springs" instead of "springs too stiff" or " too stiff springs"
Regards,
Ken

That is the way they talk in the midwest. It is perfectly understandable, but sounds horrible, somewhat like eubonics. They say similar things in New York as well, only they think it makes them sound smarter.

[ROBERT CROSS]

The "relaxed towing of a diesel?"

No..... you hear what you want, tow with whatever your comfortable with.

Been towing with 3/4's since 95 with no problems, to each their own.

[barts]

Originally Posted by safari 28

Do I hear, all of us really only need a well equipped 1/2 ton gasser for ANYTHING EVER MADE BY AIRSTREAM? I suspect the mother ship is tired of repairs due to 3/4 ton diesels that are not needed and making warranty issues already a problem worse. At some point it must be surfacing what Inland Andy has been saying all along. Over rigged equals repairs. At best, removal of the springs and full air ride must be the choice if you want the so called "relaxed towing" of a diesel.

A 34' 2010 PanAmerica has a tongue weight of more than 1200 lbs and a gvwr of 11500 lbs. This is more than my 3/4 diesel is rated to pull w/ 3.55 gears. Suggestions that a 1/2 ton pickup is better suited to towing this (or other 10000 lb gvw) trailers will be met w/ some skepticism.

If your truck is oversprung (you've added helper springs, etc) and it makes your teeth rattle when hitched up, it won't be good for your trailer. There's nothing inherent in a 3/4 ton diesel that makes it ride hard - progressive springs solve that very nicely.

- Bart

[wheel interested]

Originally Posted by FlashSilver

That is the way they talk in the midwest. It is perfectly understandable, but sounds horrible, somewhat like eubonics. They say similar things in New York as well, only they think it makes them sound smarter.

[ROBERT CROSS]

Two stiff of springs on the backside do's make it more harder to forward the weight up....NY speak for, you finally figgered it out dummy.

[boondockdad]

Originally Posted by dkottum

NOTE: Be realistic when ordering heavy duty springs. Only springs heavy enough to support your loaded vehicle (not including trailer) are necessary. Too harsh of spring rate will only shorten the life of the tow vehicle and trailer, and make your journeys less enjoyable.

! WARNING: Too stiff of springs can hinder the action of the weight equalizing hitch and prevent the transfer of weight to the front of the vehicle.

This is so ridiculously vague, it's almost pointless.
How about: "Having an instantaneous deceleration with another object will make your journey less enjoyable."

[jmtandem]

I am sure a few of you have come to the same conslusion. After towing using diesel powered pickup trucks, I have concluded that weight distribution hitches really are not made for heavy front axle trucks. The diesel weighs so much more than a comparable gas engine that there is no reason to add more weight to that axle. Taking a couple hundred pounds off the axle actually allows the truck to handle better. Since the WD hitch takes weight off the rear tow vehicle axle minimizing rear end sag and/or potential overloading the rear axle and redistributes some of that weight back on the trailer axles and most to the front axle, the hitches are counter productive. What most diesel powered pickup trucks need is only sway control/ mitigation for the trailer. Hitches like the popular Equalizer are ineffective as sway mitigation unless the weight distribution feature is also used. The spring bars need some tension to work sway mitigation. We need a new generation of hitches that work for sway without much or any spring tension for use with diesels. Before some say that is already available with the chain hitches like the Husky that has the little add on sway control bar with the handle that dials in the amount of sway needed, forget it! Those are pitiful for small trailers and almost useless for larger ones. Maybe a hitch manufacturer will address this issue, make a hitch that predominately addresses sway and make the hitch 'Airstream friendly' for the (apparently) special AS needs. The hitch would accommodate a shock of some kind to soften the really big bumps??

As long as we read/follow the hitch instructions, measure the amount of spring tension with a tape measure from the tow vehicle's front bumper or fenders to the ground and the same at the rear of the tow vehicle and then try to add more weight back to the front axle to compensate for the rear end drop, it will not work. Most pickup trucks sit rear end high from the factory, if the rear drops two-three inches and the truck sits level there is no need to add that measured truck to ground difference back to the front axle or the trailer axles. When the truck sits level, it handles better, the front axle is slightly unloaded, and all that is needed is sway mitigation. My truck actually handles better with the trailer attached (1000+/- tongue weight) than empty. And without jacking up the tension on the spring bars to mitigate the two or three inch drop, we are minimizing damage to the tongue. It can be a win win situation.

[dkottum]

Vague indeed 'joe, and I have been curious what others thought about it. To me there is a call to use common sense in selecting a tow vehicle, that it is important to match tow vehicle and trailer.

There are extensive opinions, some experiments, about proper tow vehicles, hitches, and weight distribution bars. The consensus is that too light of equipment is simply dangerous, not so agreeable on too heavy equipment. I suspect you could weld all the axles to the frames, install a stout w.d. hitch, and take it to the CAT scales and properly distribute the weight among the axles. But when it is moving down the road - bumps, dips, rises, corners, accelerating and braking - everything changes. The suspension must be compliant enough to keep the rubber firmly on the road, and the hitch connection must be compliant enough to prevent large stresses to be applied to the tv and trailer in these real-life conditions, meanwhile not transferring excessive lift or pressure to the axles of the tv.

I understand why Airstream would not try to be more specific, considering all the factors involved. It is not as easy to understand why hitch builders can make definite recommendations without considering suspensions of tv and trailer.