First Towing Experience 2021 Yukon Denali - 5300lb trailer, with and without stablizer

[swathdiver]

At the risk of going on too much - one of the features listed for the 2021 Yukon Denali w/Premium package is "Trailer Sway Control"....
View attachment 408389
Obviously it can't fix 'bad trailer loading' but I wonder how effective this is. And I don't know how to tell if the vehicle actually has this feature. For example, our old vehicle got sway (on same trailer) at ~53mph and the Yukon is ~58mph - so maybe this higher mph is partly due to ~7% additional stability due to this feature?

Interested to understand more about how much this can compensate. Its it more of a minor marketing point or something more.

I ask because I slowed down IMMEDIATELY at the first sign of sway... that 2" back/forth visible in the mirror. Clearly one should not continue driving under this condition. But just for the sake of understanding, would the traction control keep sway from becoming a catastrophic wreck more than I was thinking or was that 2" back/forth in spite of the anti-sway control and as dangerous as I'm thinking?

Yep, that was introduced in 2012 along with Hill Start Assist, pretty nifty.

 

[tagexpcom]

And now that I'm aware/searching on this topic, I see this Curt True Course (brake oriented) Trailer Sway Control - https://www.curtmfg.com/part/51202 - and wondering how effective.

 

[Geotrash]

At the risk of going on too much - one of the features listed for the 2021 Yukon Denali w/Premium package is "Trailer Sway Control"....
View attachment 408389
Obviously it can't fix 'bad trailer loading' but I wonder how effective this is. And I don't know how to tell if the vehicle actually has this feature. For example, our old vehicle got sway (on same trailer) at ~53mph and the Yukon is ~58mph - so maybe this higher mph is partly due to ~7% additional stability due to this feature?

Interested to understand more about how much this can compensate. Its it more of a minor marketing point or something more.

I ask because I slowed down IMMEDIATELY at the first sign of sway... that 2" back/forth visible in the mirror. Clearly one should not continue driving under this condition. But just for the sake of understanding, would the traction control keep sway from becoming a catastrophic wreck more than I was thinking or was that 2" back/forth in spite of the anti-sway control and as dangerous as I'm thinking?

Our 2012 has the factory trailer brake controller, which is a requirement for using the trailer sway control in the vehicle control software. I’ve had it engage twice. Once while pulling our camper down a mountain on I-64W in windy conditions and an a55hat cut across in front of us to make an exit at the last second. Had to swerve to miss him and the stability control light illuminated for a few seconds and I could feel the system engaging the trailer’s brakes to straighten us out in short order. It’s an excellent safety feature.

And yes, that 6.2 has plenty of power for pulling - so much so I have to remember to keep my foot out of it or next thing I know I’m busting the speed limit uphill. The factory radiator and transmission cooler also have adequate capacity to keep everything cool - even when pulling a heavy trailer out of Death Valley in the summer.

 

[intheburbs]

At the risk of going on too much - one of the features listed for the 2021 Yukon Denali w/Premium package is "Trailer Sway Control"....
View attachment 408389
Obviously it can't fix 'bad trailer loading' but I wonder how effective this is. And I don't know how to tell if the vehicle actually has this feature. For example, our old vehicle got sway (on same trailer) at ~53mph and the Yukon is ~58mph - so maybe this higher mph is partly due to ~7% additional stability due to this feature?

Interested to understand more about how much this can compensate. Its it more of a minor marketing point or something more.

I ask because I slowed down IMMEDIATELY at the first sign of sway... that 2" back/forth visible in the mirror. Clearly one should not continue driving under this condition. But just for the sake of understanding, would the traction control keep sway from becoming a catastrophic wreck more than I was thinking or was that 2" back/forth in spite of the anti-sway control and as dangerous as I'm thinking?

The best way to stop sway is to apply tension to the hitch. Unfortunately, when excess sway starts (usually from a gust/crosswind or a passing semi) the natural reaction of most folks is to lay off the gas or tap the brakes - both of which do the exact opposite of what is needed.

Proper response to sudden/induced sway is either:
1) Hit the gas - which is completely counterintuitive and against human nature. This goes along with what I taught my kids when something goes wrong - don't panic. Basic OODA loop - observe/think/act. Override your emotion flight/fight response.
2) Apply the trailer brakes using the lever on the brake controller. Again, this has to be practiced/trained/learned behavior and is not a typical human reaction.

One of the things I like about my Tekonsha Prodigy brake controller is the boost feature. Once we're at highway speed I crank up the boost to maximum. This way if I tap my brakes, it applies the trailer brakes much harder than the vehicle brakes to create that needed tension in the hitch to control the sway.

The vehicle manufacturers added that feature once they started offering integrated brake controllers. They're using the already-present stability and yaw sensors to apply the trailer brakes as needed to control sway. However, I would not rely on the feature solely as my only anti-sway countermeasure. I view it as nothing more than an insurance policy, and properly loading/balancing the trailer is still paramount.

On a more macro level - vehicle wheelbase is very important in towing stability. I have a 3/4-ton Suburban and half-ton Sierra crew cab. Obviously I only pull the behemoth with the Suburban. But I also have a 6x12 enclosed single-axle cargo trailer. I usually pull it with the Suburban, but I occasionally pull it with the Sierra. First time I did it was a HUGE eye-opener. The Suburban is 1000 lbs heavier, so one would think it would be the preferred/better tow vehicle. But the Sierra has an 18" longer wheelbase that makes all the difference. Much more smooth and comfortable in the Sierra - much less tail wagging the dog. The difference is frankly night and day.

So coming back around to OP's short-wheelbase Yukon and short-wheelbase trailer - yes, one can understand that the rig is REALLY going to want to sway. Longer moment arms have more rotational/yaw inertia. Short moment arms are going to be twitchy. Think of a tightrope walker - is the balancing pole in their hand long or short? The longer the pole, the better the stability. OP has the opposite, unfortunately.

 

[tagexpcom]

1,500 mile follow up....

Recap - we're pulling a 5,400lb 7 x 14 dual axle trailer w/650lb tongue weight on our Magnetic Ride (but no air bags) 2021 Yukon Denali 6.2L and 22" wheels.

- With the Blue Ox TrackPro Weight Distribution the rear sinks ~1.25" and the front rises ~1/2". This makes the vehicle appear level as prior to hitching up - the rear is 37.5" (top of fender thru center of wheel) compared to 35.75" at front.

- Installed a Curt 51170 break controller - works fine and looks nice.

- Using a GEN-Y GH-305 10" Drop Hitch to bridge the height gap - works great.

We've driven 1,500mils, up to 70mph with no issues. The vehicle never seems 'under strain' / runs and shifts smoothly up/down 6,000ft mountain roads w/4-6% grades. Averaging just over 9miles per gallon with mountain driving.

Real pleasure to drive and more than capable for our towing situation.

 

[dbphillips]

Sorry to bring this back from the dead, but I’m techy.

Did you have water in the tanks to begin with? If not, you could have added water to see if it eventually settles down. But at about 80 pounds of propane (or perhaps 80 pounds of generator, as someone brought up), I would start by moving them to the same distance ahead of the trailer axles as they are behind and see if that stabilizes it. But that doesn’t help the sag, so you want the WDH anyhow.

There are two other solutions I’m investigating: Coil sumo springs (once they go on sale, yikes!) and variable rate coil springs.

Hopefully, someone steps up soon and makes an air shock that lets us add some height on demand.

 

[tagexpcom]

Sorry to bring this back from the dead, but I’m techy.

As OP, no problem for me.

Did you have water in the tanks to begin with? If not, you could have added water to see if it eventually settles down. But at about 80 pounds of propane (or perhaps 80 pounds of generator, as someone brought up), I would start by moving them to the same distance ahead of the trailer axles as they are behind and see if it stabilizes it.

The design is fixed with existing things; however, based on my new/better understanding I'm planning to add 150lbs of battery mid-trailer + mount some 5gal Jerry cans (maybe 5gal on each side) mid-trailer = 70lbs?. Adding 220lbs mid-trailer will bring total trailer weight up to 5,500lbs.

But that doesn’t help the sag, so you want the WDH anyhow.

The Blue Ox Trac Pro WDH stabilizes things nicely (70mph is rock steady now) with 650lb tonque weight yielding 1" rear sag and 1/2" front raise.

There are two other solutions I’m investigating: Coil sumo springs (once they go on sale, yikes!) and variable rate coil springs.

I saw a recent post with a link to these 35% 'tougher' springs - https://www.hdcoilsprings.com/produ...burban-tahoe-yukon-yukon-xl-rear-coil-spring/ - and was wondering if this would reduce the 1" sag to maybe 1/2"? and if that would matter. But other youtubes I see show that WDH is the main factor in promoting stabilization - rather than being 'more level'.

Plus adding 220lbs mid-trailer would help a bit as well.

Hopefully, someone steps up soon and makes an air shock that lets you add some height on demand.

I have the medium package which has magnetic ride but not air-ride - and I'm not seeing an easy retrofit of the air-ride feature and it wouldn't integrate into the computer + no control for ride-height adjustments as the Ultimate package has.

At 1" rear sag + WDH it's stable and 1" isn't that bad and the ride is fine. But I do wonder about trying the stiffer rear springs as this seems like a low-risk, reasonably priced upgrade and I'm not worried about a stiffer ride.

Any opinions or discussion welcome!

 

[23 Yukon Ultimate]

The trailer tongue needs to be slightly lower than level, or at least no higher than level. Pics look like it's up.

There are lots of YouTube videos on this and they say no more then a 1/2 inch difference when the loaded trailer is hitched on car. The sway comes from to light on the front wheels. I just learned this myself.

 

[tagexpcom]

Follow up. A consensus emerged in the tread above that even though my weights are find, my trailer sway without WDH is likely due to front/back loading with little weight in middle of the trailer.

Well, I recently installed a 150lb DIY battery right over the wheels - taking the trailer from 5300lb -> 5450lbs.


Not sure if centering an extra 150lbs on a 5300lb trailer is enough to make a noticeable difference, and it might be my imagination, but it seemed 'rock solid' stable during latest tow as compared to 'very' stable in previous tows.

 

[Geotrash]

Follow up. A consensus emerged in the tread above that even though my weights are find, my trailer sway without WDH is likely due to front/back loading with little weight in middle of the trailer.

Well, I recently installed a 150lb DIY battery right over the wheels - taking the trailer from 5300lb -> 5450lbs.
View attachment 421064

Not sure if centering an extra 150lbs on a 5300lb trailer is enough to make a noticeable difference, and it might be my imagination, but it seemed 'rock solid' stable during latest tow as compared to 'very' stable in previous tows.

Cool! Where did you find the plans for the battery?