Backing Up

My thoughts are that if a receiver can't handle being significantly over its rating for a brief, slow backing event I sure would not trust it for weight carrying AT its spec when traveling down the highway. The dynamic forces when towing on a rough road are much higher.

Yep John, I see where you are coming from but you have to realize that most of us "non engineer" types would not think that way and would most likely react the same way I did.

My thought was that, without the bars, the coupler would just pivot on the ball as the trailer backed up the hill. Never gave a thought to the "push" created by the weight of the trailer and I still have a somewhat difficult time picturing that in my mind unless the trailer was almost standing on its nose.

Not arguing with you at all but just having a hard time understanding the difference in forces between that and the pulling down of the WD bars on the A frame of the trailer. In my "non engineer" mind, I see the force on the A frame (truck lift?)as much higher and more dangerous to equipment than the force applied to the trucks receiver from backing up a hill or a driveway on a grade without using the WD.

Glad to see you joining in on this discussion! :) Remember, you did ask for our thoughts! :W:B
Barney

Page 6 of the Equalizer 4 point hitch's owner manual (available online) says to not tow over rough roads, dips or back up steep inclines from level with the bars attached. I'm sure the rough roads part is referring to deep gullies and washouts that would put unusual stress on the bars, brackets and head. Our driveway is at a slight incline with a gutter. Even that makes the Equalizer and Reese groan and creak backing in.

BarneyS wrote:

drsteve wrote:

Grit dog wrote:

drsteve wrote:
I have never removed my WD bars for backing. Keep in mind that your hitch receiver may not be rated to carry the full tongue weight of your trailer without WD. There's a weight sticker on the receiver.

Keep in mind that weight rating is taking into account the dynamic loading possible while towing at speed, bad roads, etc. Backing into the driveway is a nearly static condition and quite unlikely to cause any damage other than heartburn for some.

Note JBarca's comment, above: "When you back up with no WD bars, especially up a grade, even a slight grade, the truck receiver is taking a lot of bending torque and can start issues forming in the receiver that may later rear their ugly heads down the road."

I believe that John (JBarca) misspoke when he typed that comment. The bending torque during backing up a grade occurs when the WD bars are in place and tensioned, not when they are removed or not tensioned.
Barney

Hi Barney,

Thanks for joining in however my comment was correct per my train of thought. Think about it this way and see if you now agree.

With no WD bars on the hitch, the receiver is then in weight carrying mode. All the tongue weight is then acting down on the tow ball in a dead weight mode. The hitch shank of a WD hitch is longer then the standard draw bar which even more aggravates the issue. All that dead weight hanging approx 14 to 16" or more behind the receiver pin box is creating a bending moment down creating a high torque in the receiver. The hitch shank will be hanging down with no upward support from the WD bars.

When the truck starts backing up and worse when the camper is going up a grade and the truck on the level, the hitch shank will bend down even further as there is nothing to reverse that downward movement on the tow ball like when the WD bars are on. If the receiver is not rated for the dead weight you can easily go over the rating of the receiver and possibly beyond the safety factor built into it. First you are already over the towing weight carrying limit and then with the truck backing up, it is pushing the receiver down even harder trying to push the camper up a hill. The dynamic start and stop create a good "jolt" into the receiver with higher torque rotation then seen with normal WD towing.

OK that was my thoughts on this. Did I state something not right or miss something?

I do agree, that when backing up with the WD bars on that the receiver does see a high torque. But...there is always one of those buts... when the WD bars are on and you start the backing up and the camper is going up hill, then the WD bars start gaining tension just like you said. But, the WD bars then act with increased tension and that lifts the back of the truck up higher due to the increased tension counteracting the downward force and it will keep lifting up until the WD bars come into equilibrium with the amount of added tension. We have nicked name this "truck lift" a long time ago with a Rob Gratz discussion... Remember that?

When you are in a dead weight situation, there is no truck lift. All the forces just keep rotating the hitch shank down. No WD bars to lift it back up.

I have seen this with my own eyes on some of the lighter receivers and it does not look good with no WD bars on. Putting all that stress into the pin box welds is not a good thing. If you have a marginal weld or a bad weld, it is the first to get high stress into the start of a crack. Then as normal towing occurs, mile after mile that small stress riser has the ability to manifest itself into a bigger problem. (this is known as low cycle fatigue)

If the original poster has doubts, they should call the receiver manufacture and ask them, is it OK to go over the weight carrying limit by XXX# and then start backing up hill with a Y,YYY pound camper and will this affect my warranty? What does one think their answer will be?

Thoughts?

Thanks

John

drsteve wrote:

Grit dog wrote:

drsteve wrote:
I have never removed my WD bars for backing. Keep in mind that your hitch receiver may not be rated to carry the full tongue weight of your trailer without WD. There's a weight sticker on the receiver.

Keep in mind that weight rating is taking into account the dynamic loading possible while towing at speed, bad roads, etc. Backing into the driveway is a nearly static condition and quite unlikely to cause any damage other than heartburn for some.

Note JBarca's comment, above: "When you back up with no WD bars, especially up a grade, even a slight grade, the truck receiver is taking a lot of bending torque and can start issues forming in the receiver that may later rear their ugly heads down the road."

I believe that John (JBarca) misspoke when he typed that comment. The bending torque during backing up a grade occurs when the WD bars are in place and tensioned, not when they are removed or not tensioned.
Barney

Grit dog wrote:

drsteve wrote:
I have never removed my WD bars for backing. Keep in mind that your hitch receiver may not be rated to carry the full tongue weight of your trailer without WD. There's a weight sticker on the receiver.

Keep in mind that weight rating is taking into account the dynamic loading possible while towing at speed, bad roads, etc. Backing into the driveway is a nearly static condition and quite unlikely to cause any damage other than heartburn for some.

Note JBarca's comment, above: "When you back up with no WD bars, especially up a grade, even a slight grade, the truck receiver is taking a lot of bending torque and can start issues forming in the receiver that may later rear their ugly heads down the road."

drsteve wrote:
I have never removed my WD bars for backing. Keep in mind that your hitch receiver may not be rated to carry the full tongue weight of your trailer without WD. There's a weight sticker on the receiver.

Keep in mind that weight rating is taking into account the dynamic loading possible while towing at speed, bad roads, etc. Backing into the driveway is a nearly static condition and quite unlikely to cause any damage other than heartburn for some.

Yesterday I installed an Equalizer 4 Pt hitch to replace my Reese HP wdh. I went to a large parking lot where I could make a full lock u turn to check turning clearance with the hitch. Bumper to trailer got about as close as possible without contact. The hitch bars were still within their L brackets and nothing in a bind. Your Husky should be the same. The concern, aside from turning too sharp and making contact with truck and trailer, going over a deep dip or backing up a steep driveway and over stressing the spring bars. Other than that, there should be no need to remove the spring bars.

Thanks for the replies, very helpful.

LarryJoe50 wrote:
My question is when backing up do you still have the same degree (backing angle) of backing with or with out weight distribution systems. I use an Husky Center Line Weight Distribution System. And I have to back up into my driveway at a pretty sharp angle and my front view is not clear because of trees. Hope I was clear enough.

Hi Larry,

To your first question, most hitches have a max angle of turning. Meaning when you reach the max angle, going beyond it something will bind in the WD hitch and may break or bend. Also some hitches due to the way they are made can turn sharper one direction then the other.

The are several variables on a camper and truck setup that can affect the max turning angle. Not every truck and camper create the same max angle even if they used the same WD hitch. LP gas tank hangs out different, the front of the camper built different, the truck bumper and the receiver as made different etc. The best way I have found to find out this max angle is to test it.

With the help of a spotter, back up or drive forward slowly. The spotter needs to watch the hitch for binding and the camper or truck bumper which may hit the camper before the hitch does. When that max angle is found, then while in the truck look at the camper using all your mirrors and try to implant in your memory how far that looks. Do this for a left and right turn. Then try real hard to not approach that hard of a turn.

The hitch does not know if it is going forward or backwards on how the max angle was obtained. It can get into that max angle either direction. However often times you can find that max angle easier when backing up into a tight spot as you are maneuvering at slow speed and cracking the steering wheel many times as far as it will go.

Some folks remove their WD bars when backing into extreme positions. I would recommend this only be done if the dead weight rating (weight carrying rating) on your truck receiver and your WD hitch head in weight carrying mode allow it. When you back up with no WD bars, especially up a grade, even a slight grade, the truck receiver is taking a lot of bending torque and can start issues forming in the receiver that may later rear their ugly heads down the road.

Hope this helps

John