Broken pin box

goducks10 wrote:

B.O. Plenty wrote:
I thought this only happened to Lippert frames? It looks like the highly touted Arctic Fox isn't without frame problems either.

B.O.

1 14 yr old AF against lots of newer Lipperts. I'll put my money on Northwood. Not sure when Northwood started building their own frames. Was it from the get go or latter?

Northwoods made the frame on my 99 24-5N

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

Speculation was he got it stuck, rocked it hard back and forth, was in an uneven pitch, really twisted,??
Don't really know.
I will try to post pics later.
The people at Northwoods are great to deal with, but hard to speculate. They have seen it, but rarely. It was cracking near the welds of course, that's the stress, but the frame was cracked around the welds.

How would an owner "severly stress" the pin box?

B.O. Plenty wrote:
I thought this only happened to Lippert frames? It looks like the highly touted Arctic Fox isn't without frame problems either.

B.O.

1 14 yr old AF against lots of newer Lipperts. I'll put my money on Northwood. Not sure when Northwood started building their own frames. Was it from the get go or latter?

Of course when we have an issue, the RV dealer is usually the first thought that comes to mind. But generally, if you rally want something done quickly, you're better off with an independent shop. A welder, or a big rig trailer specialist, etc. Best to get a good local reference, too.

Glad it all worked out for you.

A 14 year old trailer? Been through several owners? That's a pretty good record for Arctic Fox.

I thought this only happened to Lippert frames? It looks like the highly touted Arctic Fox isn't without frame problems either.

B.O.

I hope it will be fine. So sad when a dealer just doesn't care. Hopefully you get up there in good order and get everything fixed correctly.