Any idea about this??

If I'm understanding you correctly {the slider pins were not releasing} and it is a old Trailer, if that is the case and the trailer has a bar type handle for the pin's and he is alone he can take a pair if vice-grips and lock the handle the handle in position as far up as he can get it and then take a sledge hammer and beat the pins in [there will be 2 or 4 pins] or have someone else lift up on the handle while he rocks the Truck forward and backward.

 

Or maybe your saying the Trailer was sitting on top of the pins, if so then someone slid the tandems too hard and when they broke lose and the Trailer jumped up on top of the pins. It can happen with old Trailers.

 

I dont get it....

 

Ida pulled it just like it was. No need to hurt yourself.

 

If i understand this correctly, this is a older trl. with that old style bar, the area that the bar rests on is not that great of a area and the bar could slip off real easy, when you pick up on a bar like that the pins are spring loaded and putting a load on the bar when the pins would not move and cause the bar to slam down on the driver.

 

Easiest option usually.

 

The best thing for those old tandem puller/pins is a can of PB blaster or Liquid Wrench. They usually come with a little red straw so you can aim the spray pattern into specific spots. On a fussy trailer I'd spray the tandem pins and any moving joint on the pulling mechanism. Sometimes the frame they slide on would need some too.

Best thing to do is spray those parts before you drive over to where you need to slide the axles. The trailer bouncing down the road after hitting it with the Liquid Wrench usually breaks everything loose.