New Andersen WD hitch

Ron Gratz wrote:

Mkos1980 wrote:
Heres a nice post from another site which explains some more.
Anderson Hitch post

Even more discussion can be found at

FOREST RIVER FORUMS -- Andersen Hitches

Just don't be confused by one person's persistent insistence that the chain linkage cannot prevent the ball coupler from pivoting on the ball.

Ron

Ron,

Thanks for the link. Seems the discussion is on ongoing on the FR forum. They have not yet did a deep dive into the mechanics of hitch.

We have one issue here that the group on RV.net discovered and maybe you can shed your opinion on this.

Recapping this much we have sorted out.

• We understand the high friction of the anti sway feature. Similar concept as the hitch in Europe I linked to.
  
  
• We understand how it has the ability to distribute weight. How effective it is and sensitive it is is another question.
  
  
• We have determined that the tow ball will be forced into the coupler latch under high force during WD. We question if the latch can handle this high force long term.
  

Now to the unknown part. This one is going to take some figuring for sure. You saw my estimates on the chain loads for a given tongue weight, on a certain TV WB, TV overhang and ball to TT distance. They may be off some but I feel they are in the ball park (I think...) I used your excel sheet on WD to determine the WD chain loads. LOL

From the Andersen WD chain loads it is going to be mixture of forces acting on the chains along with which direction they act on the tow ball, TT ball coupler front and the TT ball coupler rear safety latch.

Chains towing the camper When the TV is stopped or rolling forward at low speed, the chains are pulling the camper. The chain force is high enough that is it pulling the camper forward and seating the tow ball into the latch side of the ball coupler. Clearance exists between the ball sphere and the front part of the coupler that normally pulls the camper. The rolling resistance of the camper on the 28.3" OD tires on concrete or black top is less then the chain force under these conditions.


Tow ball towing the camper There may be a point where the wind drag on the front of the camper or up hill (gravity) loads increase enough that the TT drag is higher then the WD tension in the chains. In this case the TT would shift backwards by the clearance in the coupler when the wind drag force overcomes the WD chain force. The tow ball leaves the coupler latch and now becomes seated into the front part of the ball coupler. The TT is now pulled by the ball coupler.

There are other upsets that shift force direction on the tow ball depending on if the ball coupler front portion is pulling the camper or the WD chains. That is if the wind drag was large enough to cause a shift in the 1st place. Some concern areas are:

• When the TV slows down from high speed, the forces may shift back to the coupler latch and the chains start towing the camper. .
  
  
• A large bump by the rear TV axle creates a large impact and can increase chain tension. It depends on which force is greater as to if the WD chains are pulling the camper or the ball coupler.
  
  
• At high speed when the brakes are applied, if the brake controller leads the truck as many set their controllers, the TT drag will increase and there will be a new point where the chains start towing the camper once again.

What we do not know yet, is on a 1,400# TT tongue weight, 9,200# GVW TT does the wind drag or up hill drag ever get high enough to let the ball coupler tow the camper? And any guesstimate on what speed that may be? I picked those weights only because they line up with my camper. The issue can occur under other TV and TT combos as well.

The high load on the coupler saftey latch is a large concern. If the TT seats and reseats back and forth constantly as you tow down the road, the fatigue on the coupler saftey latch is something to think through.

Do you have any thoughts on this and do you see this the same as some of us do?

Thanks

John

Edited: 1-22-12 Tweaked words to better get certain points across