2015 Denali Towing Sway

[Ejmi]

https://www.weigh-safe.com/
Done a lot of towing in a variety of rigs (10 years Coast Guard stations, 2 years at marina, 5 years in Alaska w snowmobiles, tow 5,000 lb boat thousands of miles yr).... tongue weight/distribution is soooo important. And most folks are not aware. If a trailer sways, something is wrong. If’n you’re asking the ?, man that weigh safe hitch

 

[510man]

The above suggestions are what usually causes the sway problem. I worked with a trailer that we struggled to get to pull straight and it turned out to be an under spring cambered axle installed in an over spring trailer. Net result? Trailer had positive camber. If you drove behind it, it looked like Mr McGoo's car with the tops of the tires angled outward. You want zero or negative camber on a trailer. I can't think of an example when positive camber would ever be a good thing on a trailer.

A couple of suggestions not previously mentioned:
1) Check the trailer alignment. A bent spring or axle can cause the sway. You can check your alignment with a piece of string. Tie it around the base of the ball and stretch it too the inside edge of the tire. Mark the string with a Sharpie. Now do the same thing on the other side making sure to measure to the same point on both tires. If they are not the same, you're out of alignment. The question is "why"?
2) If your trailer has a cambered axle (likely), the tongue height will alter the alignment tow-in/tow-out. If the tongue is not level under load it will sway. A raised tongue with a cambered axle results in tow-out. Tow-out will cause the trailer to nibble and dart, which results in sway. Consider ordering a non-cambered axle. Cambered is better under heavy load. However, if the trailer is pulled by multiple vehicles with varying hitch height, the non-cambered axle can help. Why? Without camber, the hitch height will not change the toe-in/toe-out. It will remain at zero degrees regardless of ball height helping it to pull straight.
3) Get a Hensley Arrow. Expensive but it works. https://www.hensleymfg.com/
4) Hoping you have electric brakes on the trailer given the load. If so, you can manually drag the trailer brakes slightly from the brake controller to correct the sway. The need to do this would be rare if the trailer alignment, hitch height and load are all correct.

I put a non-cambered axle in the problem trailer and it pulls perfectly now regardless of tow vehicle. It's a Boy Scout trailer so it's pulled by every pick-up or SUV you can name and loaded differently every trip. It pulls perfectly behind all of them regardless of hitch height now that it has a non-cambered axle in it.

Hope it helps you find your problem.

 

[orchidcrazy]

Maybe it's just me, but most sway issues are due to an improper setup - you're not level or you're towing too much or you're load isn't distributed properly. Why in the world would you switch out axles or go to the expense of a Hensley without simply weighing the rig and seeing if it is properly set up? The Hensley is a great product but a good set up negates the need unless it's something you really want - and the Hensley doesn't negate the need for making sure your set up is correct!

 

[510man]

Please go back and re-read what I wrote: "The above suggestions are what usually causes the sway problem", which is agreeing that leveling, loading balancing, etc are usually the problem.....but not always.

With respect, you stated what you thought earlier in the thread so what new information did you add to help the OP resolve the problem? I'm simply giving him/her some other things to try if leveling, loading balancing, etc. did not yield positive results.

Why would you switch axles? Your question tells me you don't understand alignment geometry and the impact it has on how the trailer pulls and how the hitch setup changes the alignment geometry from vehicle to vehicle. You change the axle if the alignment check show it's out of alignment due to a bent axle or, as I found, the wrong axle is in the trailer. Don't assume the trailer manufacture got it right. They make a few mistakes too. The idea is to eliminate the known variables. Alignment is a known that is easily checked. To be clear, you can load level and balance your load in perpetuity and it won't compensate for a trailer being out of alignment.

 

[Josh61513]

And, any cargo rear of your rear axle counts as tongue weight.

Weight distribution on a trailer should be about 60% front- 40% rear.

This is bad information. Weight in the tow vehicle behind the rear axle does NOT count toward tongue weight. It may be a consideration for spring bar sizing etc. on a weight distribution hitch but by this same logic in order to tow a 3,000 lb. trailer you would want 300-450 lbs. of tongue weight. If you have 500 lbs. in the hatch behind the axle you don't want 0 to negative tongue weight of the trailer! You'll experience a whole new level of trailer sway.

In my experience most trailer sway comes from insufficient tongue weight, followed 2nd by excessively high hitch weight. The trailer should ride level to slightly downward (tongue closer to the ground), not upward. These new suburbans & tahoes with hitches through the bumper often need a really big drop hitch.

I tow a heavy car trailer with my 2015, several times with 6,000-8,000 lbs. and have never had an issue with trailer sway. I do use weight distribution that has been properly setup.

 

[Floep]

Sway is caused by centre of gravity of the trailer being ahead of the trailer axle. Remedy as quoted before, is to have 10 to 15% of the trailer weight on the tongue. Then check if the tow vehicle is at the same angle to the road with and without the trailer, the hitch weight may unload the front axle too much causing too light steering. Cure is: spring bar hitch, to bring tow vehicle weight distribution back close to non trailer level. All other idea's are just that. Idea's Physics is the cure as above.

 

[dbbd1]

This is bad information. Weight in the tow vehicle behind the rear axle does NOT count toward tongue weight. It may be a consideration for spring bar sizing etc. on a weight distribution hitch but by this same logic in order to tow a 3,000 lb. trailer you would want 300-450 lbs. of tongue weight. If you have 500 lbs. in the hatch behind the axle you don't want 0 to negative tongue weight of the trailer! You'll experience a whole new level of trailer sway.

In my experience most trailer sway comes from insufficient tongue weight, followed 2nd by excessively high hitch weight. The trailer should ride level to slightly downward (tongue closer to the ground), not upward. These new suburbans & tahoes with hitches through the bumper often need a really big drop hitch.

I tow a heavy car trailer with my 2015, several times with 6,000-8,000 lbs. and have never had an issue with trailer sway. I do use weight distribution that has been properly setup.

Yes, I should have clarified that...

https://www.etrailer.com/question-56529.html

 

[racefreak24]

probably your Struts are Junk