WDH with Swing-away Tongue

[Mr. Adventure]

Originally Posted by Barry C Anderson

My spring bars only came up high like that after the swing hitch plate was bent 3/4 inch and the whole swing hitch was tilted 3 inches upward. Yes, you are right, you need to reduce the number of links on the chain as much as you can before backing up a steep abrupt grade. With my setup 4 links is the full set up and 3 links is only partly on and 2 links are slack. I probably bent the swing hitch when I was on the full link setting. However in my case you can't take the equalizer bars off completely because then the front on the trailer jams on the driveway and then I need to get a 3 ton floor jack to lift the front of the trailer off driveway. If I had reduced the WDH setting to 3 links before backing up, perhaps it would not have bent. The thing that exagerates it worse in my case with the way my street is sloping, is that I am backing up with the right side of my trailer on the high side of the driveway and that is the same side of the trailer that has the locking pin on the swing hitch and it is the force on the right side locking pin that bends the vertical plate on the swing hitch. My spring bars are 750 lb.
What others could learn from this is that if you were to say turn around and back up a steep driveway anywhere in the country this could perhaps happen.

There is no way that the spring bars should be strong enough to bend a trailer frame, because the trailer frame needs to be a whole lot stronger than those small spring bars. Can you post some pictures showing how it's bent?

[scrubjaysnest]

Originally Posted by Mr. Adventure

There is no way that the spring bars should be strong enough to bend a trailer frame, because the trailer frame needs to be a whole lot stronger than those small spring bars. Can you post some pictures showing how it's bent?

I need to get my statics hand book out to be sure but best I can remember is once you start the TM up the effective TW shifts from the same on all three axles to more force at or near the hitch head. On our '11 2720SL there is a slight gap in the swing hitch between top and bottom of the frame. Its only about 1/4 inch but it is something I may have to resolve if I can ever find a WDH that works on our TM.

[Wavery]

There is absolutely no upside to backing up a steep hill with the WDH bars on.

The forces when backing while the trailer and TV are at extreme angles changes everything. The spring bars are no longer just spring bars. The force is no longer just vertical, it is also horizontal (due to the upward angle of the trailer in relationship to the hitch). The spring bars are actually trying to lift the rear wheels of the TV off of the ground while at the same time, trying to assist in pushing the vehicle up the hill. With a 750# WDH, I'm a little surprised that this activity didn't bend the spring bars. That's why I thought it might be a much higher rated WDH......

The WDH is designed to transfer weight to the front wheels of the TV while towing down the highway to improve braking and steering. They are not designed for backing up a sharp incline like that and are no longer needed. However, due to the lower bumper from the addition weight on the rear axle, the OP may need to install Air-lifts for the additional rear bumper height.

In fact, I think that the OP would find it easier to push the trailer up that grade w/o the WDH. The lack of weight on the front wheels is not an issue and the 500# of tongue weight is not going to hurt the hitch or TV in any way. In fact, some people put a receiver on the front of the TV (with just a draw bar) for just these types of scenarios. My SIL does that with his 35' travel trailer (800# tongue wt) and just has a class III hitch on the front of his truck.

I was going to say to think about adding some air bags to the TV too....problem solved.
They work well.

[Bill]

Originally Posted by Barry C Anderson

... in my case you can't take the equalizer bars off completely because then the front on the trailer jams on the driveway and then I need to get a 3 ton floor jack to lift the front of the trailer off driveway.

Go to WalMart, and buy a hitch with a 2-inch or 4-inch rise (about $25 including the ball). When you get ready to back up the driveway, use this hitch instead of your big one. No scraping the hitch on the driveway, no springbars, no problems. Works for me!

Bill

Thanks for the tips but I solved the problem as I noted previously by getting rid of the swing hitch. I first responded because someone asked if anyone had a swing hitch that failed. Someone also in the recent posts asked me if I had a picture of the swing hitch with the bent vertical plate so I included one for info. Thanks again for all the advice. I am fine now.

[Mr. Adventure]

Originally Posted by harveyrv

There is absolutely no upside to backing up a steep hill with the WDH bars on.

There's no downside, either. The WDH lifts the middle and loads the ends, moving a few hundred pounds, exactly the same way whether you're stationary or rolling frontwards or backwards, and whether you're on an incline as well. You should take the hitch bars off if you don't mind your front axle being unloaded or you don't want your middle lifted, for example if the rear of the trailer bottoms out as you go from the street to the driveway incline. If backing the trailer on the driveway involves sharp turns, I can understand fears of the bars binding. With front wheel drive, as I have, you might benefit from the extra traction from having the WDH fully engaged.

The axles of the TV and the trailer carry a few thousand pounds, substantially higher loads than what's going on at the hitch. The frame members at the axle are the same as at the hitch, therefore you shouldn't be able to bend a trailer frame with hitch bars unless there's something seriously wrong with the trailer frame (broken/missing/poor welds, improperly built/attached swing hitch, etc).

Welding the swing hitch closed fixed your problem by reinforcing the weak spot (thanks for the pictures!). The underlying weakness you discovered at the attachment point for the swing hitch should be of continuing interest to those with swing hitches.

[scrubjaysnest]

Originally Posted by Barry C Anderson

Thanks for the tips but I solved the problem as I noted previously by getting rid of the swing hitch. I first responded because someone asked if anyone had a swing hitch that failed. Someone also in the recent posts asked me if I had a picture of the swing hitch with the bent vertical plate so I included one for info. Thanks again for all the advice. I am fine now.

I really like your solution, the swing hitch has looked like a big problem area to me since we first looked at our TM. The dealer didn't have one on the lot without the swing hitch and gave us such a good deal I figured I could handle it later. We already have a 1/4 inch gap at the bottom on the same side and that is with out using a WDH. I tried setting up the WDH when we got home from Tx but there is to much interference. Good thing two of my neighbors are certified welders, one is even nuke certified.

[scrubjaysnest]

Originally Posted by Bill

Barry / Big Bear -

As I think you observed in the narrative with the pictures, a tight turn (as shown in one pic) can cause the tip of the bar to hit stuff on the underside of the A-frame at the snap-up hook area. It can also cause the chain on the outside of the turn to snub up against the A-frame, effectively shortening it. Either one will cause immense stresses on the various parts, with the result you have experienced.

It appears to me that the biggest part of the problem occurs during a tight turn -
Bill

After reviewing this thread again and looking Barrys' picture, the next to last, I have reached the conclusion there is no way to make standard length spring bars work on a 2720SL with swing tongue. Look at the chain angle from the spring bar to the bracket. With my TV and TM in a straight line on level ground and 6 links between the trunnion bar u-bolt and bracket mine is not straight, the chain that is, or near vertical as the instructions say to have it. I still wonder how CustomRV makes it work? Longer spring bars maybe?

[scrubjaysnest]

Originally Posted by Barb&Tim

I thought the same thing, they do appear to be too high.

I know it took me an entire afternoon of trial & error settings to finally get ours adjusted properly:

Varying:
Hitch height adjustment
Hitch tilt adjustment
# of links to use

To get:
a level TM
front & rear settle on TV close to equal
and level bars that did not bind anywhere

Tim

Tim
How were you able to get the chains in the near vertical position the manual calls for between the spring bar and bracket? Are your spring bars longer then 30 inches? I would think your '10 would be identical to my '11 in the swing tongue area.

Ken