Equalizer hitch failure

Oxygen,
There is no horizontal movement of the bars.
The bars move with the trailer A frame and the L brackets move along with them during a turn or sway event. The L brackets simply hold up the end of the bars just as the chains do on a regular hitch and they provide a platform for the bars to slide forward and backward on. It is the friction of the bars on the L brackets that provides part of the sway control.

Most of the sway control comes from the steel on steel pressure between the hitch head under surface and the top surface of the bar sockets. This pressure is very high when the bars are drawn up to distribute the weight.

In the earlier photo, you can see the wear marks on the bottom surface of the hitch head from this friction between the two surfaces.
Barney

Edit: By the way, I was stationed in Champaign at Chanute AFB for four years back in the 50's. One of my best friends still lives there.

Not real common, but it can happen in a very tight turn. Like Barney said, the L-Brackets have nothing to do with it. The socket can indeed rotate that far and will barely clear the top of the nut. That's why the shank on the ball cannot extend down further then say, 1/8" of an inch or so beyond the nut.

Like I mentioned in a post above, my Equalizer brand ball barely extends past the nut, maybe an 1/8".

BarneyS wrote:
The L brackets have nothing to do wit it. All the bars do is slide back and forth on them. They do not limit the rotation of the bar sockets in any way.

The problem being discussed is the bar sockets hitting the ball stem/shank because it is too long and extends down below the upper surface of the sockets. Those sockets rotate when you make a turn and can crash into ball shank causing the socket to break or crack. You can easily see that happening in the photo earlier on this page.

If your ball shank extends down below the top of the socket, i would strongly advise you to change to the proper ball or you will likely end up like the OP with a broken hitch
Barney

yes, I plan to change it. Still not sure how socket can rotate far when the L bracket limits the horizontal movement of bar. I believe you when you say it does, it must pivot on L bracket.

The L brackets have nothing to do wit it. All the bars do is slide back and forth on them. They do not limit the rotation of the bar sockets in any way.

The problem being discussed is the bar sockets hitting the ball stem/shank because it is too long and extends down below the upper surface of the sockets. Those sockets rotate when you make a turn and can crash into ball shank causing the socket to break or crack. You can easily see that happening in the photo earlier on this page.

If your ball shank extends down below the top of the socket, i would strongly advise you to change to the proper ball or you will likely end up like the OP with a broken hitch
Barney

Trying to understand how this damage is done to the ball stem. I thought the socket rotation was limited by the L bracket. There is very little space on the L bracket for movement and can not envision how the socket can rotate into the stem when the solid bar is held by L bracket.
Noticed that my ball stem is longer than what Equalizer wants.

Metal does NOT heal and only gets worse...

It WILL fail sooner than later and when you least expect/want it to

Get it replaced NOW

Hey Teamfour,

You noticed a very small crack two days ago in the top of one of your tubes.

I would call that an issue for sure!

Teamfour wrote:

opnspaces wrote:


I had some cracks in my sockets and exchanged a few emails with Progress mfg. That's how I found out about the case hardening.

What did Progress do about the cracks? I noticed a very small one two days ago in the top of one of my tubes. The ball shank is the right one, so no issues there.

This has gotten one of my interests...design forensics

Initially thought CAST IRON from the pictures...could be steel, but why
would they harden it clean through??? The break is indicative of cast
iron or hardened steel. There was no indication of ductility in the
break

Can see why hardening is necessary, as they use the friction between
the hitch head to trunnion sockets as one anti-sway component.

This is NOT "case hardened", as that meant to only harden it on the
surface down to a specified depth....to leave the core material ductile

A case hardened would have a different crystalline structure across
the break. From hard (case) to ductile (core)

Steel tubing makes sense, as to cast that thin section would have been
costly. Assume they used cold rolled, as hot rolled requires secondary
and tertiary treatments

I'd have left it cold rolled and instead of hardening for wear attributes,
have sacrificial friction material. Just like friction bars.

As for the cracks on a setup with the proper ball shank length...think
it's with the clear through hardening and the Rockwell C number they
hardened it to. Find that number out and if it is above a certain number,
then becomes brittle

Sorry, it's been decades since my last usage of this area...but...that
number can be looked up. Am guessing it should NOT be above 35...but
harder has higher abrasion resistance...an oxymoron...

cbwallace wrote:


Glad I checked mine as I appear to have the same issue but fortunately is has not yet caused me any problems. I will address with the reseller to get it corrected.

Yep, that's exactly the reason for the length limitation on the ball shank. Good you caught it.

opnspaces wrote:


I had some cracks in my sockets and exchanged a few emails with Progress mfg. That's how I found out about the case hardening.

What did Progress do about the cracks? I noticed a very small one two days ago in the top of one of my tubes. The ball shank is the right one, so no issues there.