Bucking motion when towing

[Buzzard Bait]

New to travel trailers. I have a 34 foot Heritage Glen, pulling with a 2015 Navigator. I'm getting a bucking motion whe getting to around 45 mph. Using a weight distribution hitch and one friction sway bar. My front wheel well is within 1/2 inch of when unhitched, but rear is about 2" lower than front. Do I need to go up another link on my chains or back off a link? My truck has load leveling shocks. Does this affect anything. I have a lot to learn!

[Ford Idaho]

P metric tires or LT's?
Coil spring suspension on the rear?

[Wobbles]

Hitch bars up a notch too far?

[markb5900]

The only way to really set your hitch up is to have the TV and trailer on a flat level surface, then start adjusting links, tilt of the hitch and eventually the height of the hitch.
Takes a couple of hours of turning wrench's and adjusting to get it right.

[greg p]

Navigators have rear coil spring suspension which will make it bouncy regardless of a weight distribution hitch. If you plan on towing quite a bit you may want to invest in a set of air bags for the rear suspension. they have systems with on board compressors and a magnetic height sensor that pumps up the air bags when the suspension squats.

[Buzzard Bait]

Tires ..... Are they those round black things that my truck sits on?? P Metric or LT out of my knowledge base. Hankook DynaPro HT. I believe these are P Metric based on a quick google search. Is that a bad thing?��

[greg p]

the tire size is printed on the sidewall of the tire, it will say something like P255/75R17/ a P metric tire has a low load rating..meaning the amount of weight it can safely support. A tire that says LT255/75R17 is a heavier duty tire, the LT meaning light truck, which usually has a load range of C or D or better. Lt is best for when you are towing things.

[Buzzard Bait]

Mine are 275/55R20.

[greg p]

Yeah those aren't tow rated tires, those are passenger rated. unfortunately you may have to bite the bullet and get 5 new LT tires, don't forget the spare.

[Buzzard Bait]

So is that an indicator of the strength of the sidewall? And would that make it bounce more? Sorta makes sense if there is too much give in the tires and the coils.

[greg p]

yes that is the sidewall thickness, the more plys the better. Lt tires will make a huge difference but I believe you are still getting bounce from your coil spring suspension. Like the other poster said get everything on level ground and take the time to set all your load levelers correctly, you'll get it, it just takes time. Don't let this ruin your great camping experiences to come.

[asquared]

My old Armada had load leveling suspension. It took me multiple tries and several months to finally figure out why we couldn't get the wdh dialed in. The load leveling suspension interferes with your measurements. We would drop the TT on the ball and shut the Armada off before the load leveling suspension could kick in. If you can turn the suspension off while doing this even better. Get your measurements on a flat surface. Once you are close to front unhitched height without load leveling suspension kicked in, let it turn back on and then drive to a cat scale to weigh your setup. You will want to do this with the rig loaded to camp and all family pets etc in the rig with a full tank of fuel. This will allow you to test your setup correctly. Run through the scales 3 times (typically $9-12 for first weigh and $1-3 for each re-weigh in a 24 hr period.) First weigh will be TV no trailer. Put TV front wheels on scale pad 1 and rear wheels on scale pad 2. This will get your front and rear axle weights as well as total vehicle weight. Second pass will be truck with TT And no wdh. The tv will be done in same position as first weigh, the trailer tires will all be on scale pad 3. The difference in truck weight will be your tongue weight. The tongue weight plus trailer scaled weight equals tt weight. (If you have to skip pass two that is ok). Third pass is truck with TT and wdh hooked up. The goal is to get your front axle as close to unhitched weight as possible without going heavier. Adjust your wdh and continue to make passes until you have the weights correct. Also be aware you should have said tongue weight of approximately 13-15% of the loaded TT weight.

35 ft is a lot of TT. A single sway bar is not enough. Ideal is a wdh with integrated sway control but lacking that, get a second sway bar for the other side. Typical rule of thumb is 26' and under is single sway bar, over 26' should be integrated sway control but two sway bars is considered acceptable. How heavy is your trailer loaded not dry? What is your navigator rated for on tow capacity and payload. For payload check the tire loading sticker inside your door. What is your hitch rated for? Once you get the above weights, you can get this more accurate. Take the navigators GCWR and subtract the scaled tv weight to get your adjusted towing capacity. Take the navigator's GCWR and subtract the tv scaled weight to get your available payload. Is your tongue weight less than payload? Are you under GCWR and GVWR? Are you under GRAWR? What weight is your wdh rated for? Hope this helps you some.

[Buzzard Bait]

Thanks for all the feedback. Looks like I've got some work to do - and some $$ to spend. Not sure if I can turn off the load leveling suspension. Will have to do some homework. I can deal with the bounce on short trips, but I hope to put some miles on it. Houston to any mountains is a loooong way!

[madmaxmutt]

Originally Posted by Buzzard Bait

New to travel trailers. I have a 34 foot Heritage Glen, pulling with a 2015 Navigator. I'm getting a bucking motion whe getting to around 45 mph. Using a weight distribution hitch and one friction sway bar. My front wheel well is within 1/2 inch of when unhitched, but rear is about 2" lower than front. Do I need to go up another link on my chains or back off a link? My truck has load leveling shocks. Does this affect anything. I have a lot to learn!

How much air pressure did you have in your SUV tires at the time?


And just for assurance, the trailer.

[MickeyD]

You are probably at the weight limit or over it with a 34" trailer, plus the independent rear suspension on the Navigator is better tuned for a good ride than towing a big trailer. I have a LaCrosse 329 that is about 8600 pounds empty and 10K loaded and it overloaded a 2014 GMC Sierra with enough capacity on paper but not real life. It would pull and stop it, but the tail was definitely in control of the dog. Ended up quickly upgrading to a Ram 2500 and towing became pleasant.

[asquared]

Just like Mickey, our old Armada had enough tow capacity on paper but not enough payload. We had a very white knuckle ride even with the wdh finally dialed in. After struggling with being passed by anything on 4 wheels and lots of problems in the mountains we upgraded to an f250 diesel for our 30' TT that weighed 5700 lbs dry, 7300 lbs loaded. We still used the same weighing method to dial in the hitch. It works well. I hope dialing in your hitch solves your towing issues.

[Buzzard Bait]

You've got me worried. My TV is rated to 9200 lbs. my trailer dry weight is 6800. I thought I would have plenty of capacity. Long trips have me concerned. The independent rear suspension may counteract any improvements I try to make to the TV or hitch.

[madmaxmutt]

I don't believe you need to panic. I believe you have a 3.5 Ecoboost, so I doubt you will have any power problems. Start by providing more details on your trailer and the hitch you are using. You might also calm some fears (or confirm them) by posting the payload on your door sticker.


I don't see a 34 on the Heritage spec sheet. What model do you have? You said the dry weight sticker says 6800. What is the tongue weight?


Brand/model/weight rating of your hitch?


Those tires have a fairly low weight rating. 2403 from the mfg website.

[asquared]

The only true way to know where you stand is to hit the scales. Some have found trouble with TT length match with an SUVs. Some have used a Hensley arrow or a propride hitch to help them. These hitches are big $$$ but so is a new tv. I would get your weights and adjust your hitch before you make any other changes. If you are within all specs, upgrade the tires to LT tires (make sure your rims can handle the higher pressure or you will need to upgrade the rims too). If still squirrelly despite being dialed in, having LT tires, and a properly balanced TT then answer is a stronger tow vehicle. I have walked this walk before. I tried most of the fixes. I stuck with my reese dual cam wdh because it is a good integrated wdh. I gave up after getting pushed down a mountain. Oh and my Armada had a rated tow capacity of 9100 lbs but an available payload of 810 lbs once I put 2 adults, a small child and a 70 lb dog in the car. The Armada was rated for a 910 lb tongue weight. My TT was sitting at close to 1000 lbs tongue weight.

If your TT is 6800 lbs dry it will likely weigh 7800-8300 lbs loaded based on averages. That means a loaded tongue weight of 1014-1245 lbs (13-15% of loaded TT weight). Look at your tire loading sticker inside the drivers door for "all occupants and cargo should not exceed X lbs" or something to that effect. That is your payload. Subtract the weight of family and pets for a rough estimate of what you have left available for tongue weight.

Edited to fix autocorrect changes.

[dustman_stx]

As you can see, you are going to get all kinds of answers to this question. A lot of them involve complicated math and so on. Here's the simple answer: If you want to have a great towing experience with that rig, get a ProPride hitch. I've been down this road before(edit- very similar one as I have an F150 rather than an SUV) and I hated to spend the money. Once I did, I'd wished I had years before. You have the same size factory tires as I do. You'll find there are no LT tires in that size except for the BFGoodrich T/A KO2, which I now have. I really like them, but they are an all terrain and might not have the look you want on an SUV- your call. At the very least I'd upgrade to an XL load range tire that will accept up to 50PSI and have a higher load rating than what you currently have, but they are still a P rated passenger tire. Still better than what you have, though. So it really boils down to this- you can spend a lot of time and some money trying to put a band aid on it- you are pulling a LONG trailer with a relatively short wheelbase vehicle- or you can upgrade your tires and get the ProPride and head on down the road with a great towing experience.