Towing experience with Santa Fe (07-12)?

[endtilly]

Hi,
This is my first post in this forum. English is not my mother tongue; please excuse any errors on my part... I have just taken delivery of my new Trillium 1300 from Great West Vans (2014). Yesterday, I drove approximatly 200 kilometers (125 miles) and I found that the rear suspension was bouncing a lot! The tongue weight with the propane tank and the battery is approximatly 200 pounds, which is not that much. The hitch height has been adjusted by the dealer. My towing vehicle is a Hyundai Santa Fe V6 2012 and has a towing capacity of 3500 lbs (tongue weight 350 lbs). Has anybody experienced this problem? Do you have any suggestions (Firestone Coil-Rite Air Helper Springs, Coil SumoSprings Custom Helper Springs for Coil Spring Suspension, using a weight distribution system). I used to tow a popup trailer with the same specs (with a Suzuki Grand Vitara) without any problem.
Thanks!

[Glenn Baglo]

My buddy tows an Escape 19 with a 2009 Hyundai Santa Fe. He's never mentioned any issues like you are experiencing.
Have you actually weighed the tongue? 12 to 15 per cent of the trailer weight is recommended. If I had to guess, I would think you don't have enough weight on the tongue.

[Mike Magee]

The tongue weight can be checked with a common bathroom scale.

Assuming that the weight is 10% to 15% of total trailer weight, you could improve the situation with a weight distributing hitch like the Andersen No-Sway. I used one with my previous trailer and it smoothed out the ride greatly.

[MC1]

Good day Eric. My lovely BH is from Beauport.

On our Nissan mini van we used a WDH and still had some bounce. The van had 280,000klm's on it so I upgraded the rear shocks to heavy duty Gabriel Bruisers. Problem solved.

[Bob Miller]

A quick check on tongue weight issues can be done by adding weight inside the front of the trailer and see if that improves the situation. I have used as many as 4 packs of 36 one liter bottles of bottled water on the front couch to test the issue and you can always drink it afterwards.


Another possible issue is to check the hitch-to-ball connection for excessive play as well as the drawbar-to-receiver for looseness.

[endtilly]

Thanks to all for your suggestions!

I've just weighted the tongue: 243 lbs (approx 15% of the trailer weight), so probably the source of the problem is the Santa Fe soft suspension. What would be the best solution, weight distribution system, rear shock upgrade or both? Has anybody used the Coil SumoSprings Custom Helper Springs?

Regarding the weight distribution system, the trailer jack (with the wheel) is located outside the tongue. Can this configuration intervene with the use of a weight distribution system?

[Mike Magee]

A side mounted jack could indeed interfere with some WD hitches. Not sure if it would preclude all of them; you'd have to do some research. Maybe the HD shocks would be a good place to start after all. You know, if you have a fair bit of kid/cargo weight in the rear of your Santa Fe in addition to that hitch weight, it could be a lot for that suspension.

One more thing you can check out: the AirSafe Hitch. It has a HD air bag built into the hitch to absorb shocks, and this will dampen the transmission of motion from trailer to tug. But they are heavy units, so it would be that much more weight on your back end.

[redbarron55]

I would investigate heavy duty shock absorbers and perhaps some air bags to keep the car level.
Studies have shown that air bag helper springs give about half of the stabilizing effect of the weight distributing hitch at a much lower cost.
Part of the problem is the relative frequency of the car and the trailer. Stiffer shocks will change the damping characteristics of the rear and probably damp out the undulations with no other change. This is a problem with softer riding cars when greater weights are added. Increasing the spring rate with the air bags will also shift the frequency in the right direction. With the airbags you can adjust to level the headlights and put the hitch and trailer in the right relative positions.

[Bob Miller]

[QUOTE=redbarron55;521257] (Clip) Studies have shown that air bag helper springs give about half of the stabilizing effect of the weight distributing hitch at a much lower cost.
QUOTE]

In many, many years I have never heard that suggested and I can't possible see how that's measurable, much less possible. Do you have any references for the Studies, when they were done and who did them, and the vehicles and trailers that were tested and the criteria used?

Thanks

[MC1]

Originally Posted by Mike Magee

One more thing you can check out: the AirSafe Hitch. It has a HD air bag built into the hitch to absorb shocks, and this will dampen the transmission of motion from trailer to tug. But they are heavy units, so it would be that much more weight on your back end.

Not a big fan of the Air Safe. It moves the ball way back from the back of the vehicle giving the trailer more leverage acting on the TV.

And like Mike says very heavy.

[redbarron55]

Bob,

Please check the studies from extensive tests in 1979 by the DOT.
http://www.edccorp.com/library/TechRefPdfs/EDC-1081.pdf
http://www.edccorp.com/library/TechRefPdfs/EDC-1082.pdf
http://www.edccorp.com/library/TechRefPdfs/EDC-1083.pdf
http://www.edccorp.com/library/TechRefPdfs/EDC-1084.pdf
This makes interesting reading with a very extensive reporting of many tests with instrumentation and inclused front wheel drive cars of the period.
I would guess that the data still corresponds pretty well and the newer cars are generally better handling.
It is also interesting to note that tests were done on the 1979 Chevy Citation at weights as high as 4000 lbs!
Now you can look at some actual studied well documented and scientific.
Just because they were made in 1979 does not mean that trailers handle much differently. I think that there have been relatively few major changes in trailer dynamics in the past 36 years. Cars yes, trailers not so much. I would think that pickup trucks have changed less than cars.
If you look at the data you will see that what I have repeated is justified by the study.
Page 30 states that no matter if load leveling is ised air shocks and heavy duty suspension should be used and the rear tires be operated at the tire manufacturers maximum ratings. In no case should the manufacturers hitch vertical load ratings be exceeded.

[Bob Miller]

Sorry, I can't consider testing done on vehicles 36 years ago as applicable to current production vehicles. Suspension, braking and handling in those days was akin to piloting the Queen Mary into Long Beach Harbor at night in a fog, and adding anything was apt to improve handling. And suggesting that the Chevrolet Citation had any similarities to modern day FWD vehicles suggests that you didn't have the opportunity to drive one of the Citations.


The theory and tests I am sure are valid, but the application is out of date.

But, the question was about the claim that adding air bags being 50% as effective as a WDH. And that data would have to be much more recent as vehicles have changed substantially in the past 35 years.


And cost ? There are any number of EZ Lift WDH hitches available for well under $250, Air springs cost about $200.

[redbarron55]

OK Bob.

[Glenn Baglo]

As I understand it, air springs increase the stiffness, making it harder to compress the rear end. And, that would make for a harsher ride, but would bring your headlights back to level.
A weight distribution hitch takes weight from the rear of the vehicle and moves some to the front axle of the tow vehicle and some to the trailer axle, making for a comfortable, safe and secure ride.
I never tried adding air bags, but Derek did ( to his RAV4 ) and then installed a WDH ( and then bought a bigger tow vehicle ).
My WDH does what I want it to do. Levels the vehicle and gives me a safe ride.

[redbarron55]

The weight distribution hitch shifts weight to the front of the TV by adding stiffness across the hitch. It also add weight to the tires of the trailer as well. The proportion is roughly equal to the distance from hitch to the front and the hitch to the trailer axle. The research indicated that the majority of the stabilization is due to the shift of the weight to the trailer axle. (see sited information above).
The shift of weight to the front of the TV will tend to make the car understeer more which is a good thing towing.
Adding the air bags will stiffen the rear end which will raise the resonant frequency of the back of the TV and should be accompanied by stiffer shock absorbers which will also dampen the oscillations at the rear.
If the resonant frequency of the trailer coincides with the resonant frequency of the TV the result is the undulating ride experienced.
The fix is to shift the ride characteristics of the tow vehicle out of this range with the airbags. Their effect can be removed by deflating to 5 psi when not towing.
These will also level the rig and again research has shown that a large part of the loss of stability is the lowered roll center of the combination and the unfavorable roll couple when the rear end sags.
The easiest fix would be to add air shocks if available for the Santa Fe or air bags if not.
Of course a WDH could be added, but it seems overkill on a Trillium 1300 at 1500 lbs and (I assume 13').
Here is a post on air bags from another forum:
Air Shocks - Hyundai Forums : Hyundai Forum
Here is what I found on an adjustable shock absorber, but according to the description modifications may have to be made for it to fit:
Rancho R38RS999292 Shock Absorber and Strut Assembly | Auto Parts Warehouse
Here is a link to Monroe:
MONROE SHOCKS & STRUTS :: e-Catalog
There are few choices for the Santa Fe available.
The handling is one of the reasons I went that another VW Sportwagon to tow my 16" Scamp. The car is well damped with and without the trailer.
By the way most of the old dat form the studies on the interaction between trailers and cars is still valid and if it is actually read may add some understanding the the dynamics involved.
You cannot digest the data and tests in less than 22 minutes.
The dynamics of the trailer has not changed at all in the last 35 years and without a doubt the cars have improved quite a bit so the handling should be better. The interactions are very much the same when adding the trailer to a better handling car.
My experience with the VW has proven this to be the case. A poorly suspended TV is will not get better with a trailer attached.
Your experience may differ.

[Bob Miller]

Nope, one can't "digest" the information in 22 minutes, but they can read the 4 summaries and keyword search the documents in that period of time, and there is nothing to indicate that Air springs were 50% as effective as a WDH. Can you point to where that is supported?


BTW: I doubt if 5% of the readers have a grasp on what "Resonant Frequency" between TV and trailer even means. It's usually better to write to the level of the audience, not to mention inserting <cr>'s between paragraphs to improve readability.

[redbarron55]

Page 112 of ECD 1082 Graph show the 50% with air lift alone.
In all cases where the WDH was used the setup was level the vehicle to the max with Gabriel HiJacker shocks and then adjust the load leveling hitch to level.

Since this won't be settled they I suggest everyone get a load leveler for their 1500 lb trailer to pull with a 5000 lb vehicle.
Probably best is a 3/4 1 ton truck with WDH and just set the trailer in the back.

Of course most of us have the small fiberglass trailer so that we can tow them with a smaller vehicle so it might help to investigate what works best with that setup.
Again if you actually look at the data and graphs you will see the minimum WDH shown which is air levelers alone and no torque on the hitch!

This is about 50% of the improvement with the hitch adjusted to the max settings.
Plus this sets the TV to the correct ride height for headlights and suspension setup.
The rest of the combination is to increase the air pressure in the TV rear tires (suggested in tire manufacturers max cold) to stiffen the sidewalls and the same with the trailer. This is to increase the damping and limit the swing.

Many of the new unibody cars do not allow for weight distributing hitches (probably due to body construction of sheet metal) and for sure VW does not. They do state that additional heavy duty springs (or air shocks) may be necessary)

I don't know about Hyundai and WDH addition. There are limited choices for adding stiffer shocks as well, but the air pressures could and should be increased.

I am surprised that the trillium 1300 causes problems with a max gross weight of 5512 lbs and a max towing capacity of 5000 lbs. ( for the 2015 GLS V6). At 4000 lbs empty and the weight of the trillium at 1800 lbs the ratio is .45 and should not be a problem.

I am not trying to start an argument, but rather suggest something that will help the OP. The data is the data.