Picture 1
This picture gives the reader a better concept of what could happen should the pin on the horizontal slider bar break. For reference I inserted the cotter pins at the end of the horizontal slider bar and the fixed pin for the retaining plate (shown under the handle). I think drilling a hole and using a cotter pin with a flat thrust washer is preferable to the spring locking washer. Notice the 360-degree weld around the pin on the horizontal slider bar. This is the pin that is only tac welded. Imagine what would happen should this pin detach: The only restraint for the horizontal slider bar is the spring keeping pressure on the handle. The other fail- safe is the small triangular flat-stock piece that restrains the handle by gravity from sliding out is the spring were to break. This is a good redundant mechanical method for keeping the handle in the closed position. However, if the pin attaching the handle to the horizontal sliding bar comes out you have no restraint (either spring or the triangular flat-stock piece) of the horizontal slider bar. It can easily slide open when there is no tension against the circular locking bar. However, as Fireman stated (item 13 or this thread), when there is tension against the circular locking bar the horizontal slider bar will not move. To this I agree. But I would submit to you, if you were towing in mountains where you must pull the trailer up hills and break to negotiate hairpin turns, you then enter the arena whereby the truck is pulling the trailer under acceleration and the trailer is pushing the truck under deceleration. In the transition between the two states of pulling / pushing is where the horizontal sliding bar (with a failed pin) could possibly be pushed to the opened position, especially when negotiating a right turn or a series of right turns - ever so slightly opening the horizontal sliding bar a little each time. Once the circular locking bar is pushed over center you can kiss your trailer goodbye! Fireman has stated that the same mechanism is used it all Pullrite 5th wheel hitches. At the onset of my posting this thread I was only concerned with the Super Glide model for short bed pick-ups. After thinking about what Fireman has stated with the hitch mechanisms all being the same, I would think that the fixed hitch models would be even more susceptible to having a catastrophic failure if the pin were to break. My reasoning is that on fixed models the entire mechanism remains in one position and would be more susceptible to inadvertent movement of the circular locking bar during the aforementioned acceleration and deceleration while negotiating mountain turns (the Super Glide mechanism is turning (to a degree) with the trailer - thus negating some of the turning force on the circular locking bar. Just a thought…
Picture 2
This picture shows the horizontal slider bar in the open position. This bar, controlled by the handle, opens and closes the circular locking bar (holding the hitch to the trailer's king pin). Should the pin on the horizontal sliding bar break off there is nothing to prevent the bar from moving to the open position except the pressure of the trailers king pin under tension with the circular locking bar. As previously stated under acceleration and deceleration the tension the trailer's king pin exerts goes back and forth. Refer to Murphy's Law…
Picture 3
This picture shows the hitch mechanism with the handle attached to the pin of the horizontal sliding bar. The retaining plate is on and the hitch mechanism is ready to go. Note the pre-mentioned cotter pins versus the spring lock clips. Also you can see some of the 360 degree welding of the pin underneath the portion of the handle mating to the vulnerable horizontal sliding bar pin.
Picture 4
This picture shows a pair of six inch vice grips attached to the cover plate of the horizontal sliding bar. The picture has the handle attached to the pin. Should the pin come out (as mine and Fireman's did) the vice grips would prevent the horizontal sliding bar from opening. This would get you home in an emergency. The fallacy of this is that you must be aware the pin has detached. You would not be aware if the horizontal sliding bar pin had a catastrophic failure and came out while you were driving! The fix is just too easy to risk it…
P. S. Note:
If you can see on some of my pictures I am using slip-plate paint instead of white grease on the sliding tube mechanism. This was approved by Pullrite as an alterantive to white grease. It works great and is a much cleaner operation and overall less maintenance.