Driveway Incline Issue

opnspaces wrote:


But we all know that for every action there is an equal and opposite reaction. So doesn't the hitch weight go up and I assume substantially if he leaves the bars hooked up through a angle such as in the pictures and gives an angle like \/?

The dry weight of his trailer is 4,790 lbs with a hitch weight of 560. These weights are very similar to my trailer which when fully loaded has weights of ~ 6,000 and a tongue weight of ~ 850. So is it better to leave the WD hooked up and put a ton of weight on the hitch with the angle like a \/ or is it better to go with the bars off?

Hi opnspaces,

Good questions, I'll add some thoughts about them. Think on this a few moments.

To your first paragraph on does the hitch weight change if the truck and camper are in a V configuration? From what I know, the answer is no, the hitch weight does not change. Meaning the actual loaded hitch weight of the camper unhitched from the truck does not change.

What does change is the loading tension on the WD bars. Think of this situation which you may have encountered over the years. It is sort of a classic case of back flexing so to speak of the WD hitch. Here is the example.

You are towing down a back country road to camp. You approach a large high up RR crossing. The RR tracks may be a good 4 to 6 ft. above the road bed approaching the tracks, the road levels off a little over the tracks and then the same 4 to 6 ft down hill drop when leaving the tracks.

The truck and the camper will go into a V back flex configuration on the WD hitch when the truck starts going up the hill. The truck is up hill, the camper wheels are still on the level, they are now in a back flex condition. A similar situation exists on the way off the tracks and down the other side. The truck ends up on the level road and the trailer wheels are still up on the hill.

In both cases, when the back flex occurs, the WD bars start taking on extra tension from the hitch head rotating back towards the camper when the truck moves. The WD bar tension increase is sort of like tilting the hitch head back when you want more weight transferred to the front of the truck. Just in the back flex condition, the truck and hitch head is what is changing by the road it is driving on in relation to the TT. The trailer hitch weight does not change, the WD bar tension does change and it can be substantial pending the amount the hitch head rotated back towards the camper.

And visa versa, the WD bars will unload tension when the truck reaches the top of the hill going level over the tracks and the camper is then still going up hill. No back flex is occurring here, it is the opposite condition. The WD bar tension goes down, way down below normal tension. In this case, the hitch head rotated away from the camper in relation to the TT as the truck drives over the level tracks and the camper still on the hill unloading the WD bars. The camper hitch weight never changes, the WD bar tension does. Agree?

OK now to the second paragraph question in blue. First I'm going to talk about when the truck and camper hitched up, the WD is engaged, and both are standing still. Think about this for a moment. The WD hitch settings create a certain WD bar tension when the camper & truck are standing still. TV & TT might be on a flat surface, or at an angle to each other. At this point, the WD system is in what I call, equilibrium. Meaning, the WD bar tension is not getting any stronger or weaker. The back of the truck not moving up or down and the camper ball coupler is not moving up or down. The WD system is in equilibrium. Agree?

There is something else going on during the large WD bar tension rise during a back flex of the WD hitch. Again the hitch weight is not changing any time during this, but the WD bar tension does. I'm going to now call out a new made up term called, truck lift. I'm sure you can envision when the WD bars gain enough tension, the back of the truck will lift up. How much truck lift depends on the amount of tension increase in the WD bars. The truck will also drop down when the WD bar tension goes lower. Agree?

So yes, during the "start" of the back flex situation, the WD bar tension rises. If you go over the RR tracks real fast, the tension can spike up real fast. If you go slower, the WD bar tension rises slower. In either case, the fast over the RR tracks or the slow over the RR tracks, when the WD bar tension rises up enough, truck lift starts to occur from the added WD bar tension. When the back of the truck goes up high enough from truck lift, the hitch head angle changes again. When truck lift gets high enough, WD tension starts going down and equilibrium is approaching. Pending how long the hill is before the trailer wheels start reaching the hill, there may be a few truck lift events occurring. Once truck and camper wheels are on the same plane, the WD system is back to equilibrium. In all this, the hitch weight never changed, but the WD bar tension did. Agree?

Now do you take the bars of or leave them on during a large back flex situation? Part of this answer "depends" on your truck receiver, truck frame and the WD hitch head. If your truck receiver, the truck frame and the WD hitch head & shank are all rated to handle all the dead weight of the loaded TT tongue weight, then the WD bars can be off in my view as long as you are not dragging the ground. NOTE: I'll add one qualifier to this, as I see you have a 2001 2500 Suburban, that is one very nice truck. Hang onto it as long as you can. I had a 2003 K2500 Burb and it even had the quardasteer on it. I miss that truck. But, I would not on purpose every campout put the original GM receiver into a large back flex up hill condition that approaches the dead weight ratings on the original GM receiver of the GMT800 trucks. Two fold, the receiver itself flexing and due to the frame flex where it mounts. The original GM receiver issue is a different issue/topic. By chance, did you change your receiver off the OEM one?

If any of those components are not rated to handle the dead weight, (truck receiver, the truck frame and the WD hitch head & shank) then use the WD bars and go slow over the large back flex area. The WD tension rise is slower, the truck lift effect will start lowering the WD bar tension back down as the backing up of the truck is occurring. It might truck lift a few times, but it is all slow as that one the one variable you can control, the speed of the truck. Your 850# dead tongue weight is over the GM receiver rated limit so you are into using the WD bars in my opinion. If you changed the receiver, we need to talk about the frame flexing issue if you have an aftermarket receiver on the truck.

When backing up hill from a level spot and turning at the same time, the hitch head angle changes even more dynamically. Pending the angle of the turn and the amount of up hill rate change, one of the WD bars is increasing in tension while the other is loosing tension. One WD bar is holding the whole hitch when the angles gets large enough. This happens all the time while towing, just the up hill backing up with the back flex is added to all this. Again, going slow is under your control.

Does that help answer your questions?

Hope it helps

John