Broken pin box
On our way to Oregon, to have slide area repaired by Northwoods. More to that story, but in Colorado and noticed pin sitting against the front of the traler. Looked closer, and welds and frame around ...
Forum Discussion
This type os failure could happen to any trailer, although it is more prevalent with Lippert frames. The problem stems from two sources. Firat, the physics of the pin box.
Think back to high school physics class and the lever and folcrum forces problems. You have a two foot arm, "pin box arm," and 30+ feet of trailer on the other side of the folcrum point, which weighs several ton. The simple up and down motion of the trailer, aS it rides behind the truck,even on smooth roads, and the momentum of the long trailer side of the arm, puts tremendous torque load on all of the welds and tubing supporting the pin box! It becomes a simple bend it back and forth until it fails!
Lets add into this the wonderfully smooth roads our trailers are towed over. We just returned home from a four thousand mile, two month trip. The roads across the south, mostly concreete, beat us to death.
The only fix, either buy a Hensly glide hitch, or a Trailair tri glide pin box. Either one of these will reduce the shock of the road bumps, but will still not fix the physics of the lever and fulcrum problem. That can only be fixed by a structural engineer who can calculate the stresses on the frame and design a strengthening plan for a competent welding shop!
Unfortunately, RV's and trailers are like most automobiles. They are designed to sell and will last only a few years before needing to be replaced, or completely refitted from the frame up. You can bet a trailer as old as the one mentioned here has passed through several trades and the dealers do nothing but what is minimally required to sell it to another owner.
Bandaid
Think back to high school physics class and the lever and folcrum forces problems. You have a two foot arm, "pin box arm," and 30+ feet of trailer on the other side of the folcrum point, which weighs several ton. The simple up and down motion of the trailer, aS it rides behind the truck,even on smooth roads, and the momentum of the long trailer side of the arm, puts tremendous torque load on all of the welds and tubing supporting the pin box! It becomes a simple bend it back and forth until it fails!
Lets add into this the wonderfully smooth roads our trailers are towed over. We just returned home from a four thousand mile, two month trip. The roads across the south, mostly concreete, beat us to death.
The only fix, either buy a Hensly glide hitch, or a Trailair tri glide pin box. Either one of these will reduce the shock of the road bumps, but will still not fix the physics of the lever and fulcrum problem. That can only be fixed by a structural engineer who can calculate the stresses on the frame and design a strengthening plan for a competent welding shop!
Unfortunately, RV's and trailers are like most automobiles. They are designed to sell and will last only a few years before needing to be replaced, or completely refitted from the frame up. You can bet a trailer as old as the one mentioned here has passed through several trades and the dealers do nothing but what is minimally required to sell it to another owner.
Bandaid
