When Diana and I were fifth wheel shopping in 2011, we decided on a used mid-range unit that was affordable and fairly well built.  We felt that we could move to a bigger rig and truck at a later date, but we really liked the layout of the Colorado.  We had toured it at an RV show back in 2007 and immediately felt at home in it.

Our rig came with a 10″ I-beam frame and a Morryde shear spring equalizer between our 5400 pound rated leaf springs and axles.  We purposely travel light, as we know the trailer’s limits.  But RVs being subject to the constant pounding of the road, things are bound to give out now and then.  The key is to notice the warning signs before they become a disaster.  Lucky for us, Diana has a keen eye.  I was showing her something on the slide room  mechanism and she said “What is that rust on the frame from?”  We have a powder coated frame that is pretty much free of rust.  Yet there it was…a thin horizontal line of rust about one inch up from the spring mount.  I scratched at it with my fingernail and revealed this:

Well, by golly…THAT’S not good.  It turns out that we had three spots cracked in that fashion, and all were directly under the point where the cross beams were welded to the inside of the I-beam. I went into research mode and discovered that Lippert (the frame manufacturer) is well aware of this problem and has a recommended fix.  When a trailer with dual axles makes a turn, one axle is forced to one side of the trailer and the second axle is forced to the opposite side.  Those forces are transmitted upward into the frame through the springs and spring mounts.  The first thing to prevent that flexing motion are the bottoms of the crossbeams, and that’s where the cracks occurred.  A boxed frame eliminates that flexing, as there are two pieces of vertical steel instead of one.  Those frames are found on much more expensive trailers; something we prefer not to invest in at this time.

I discussed Lippert’s suggested repair with Terry at Ace Welding in Traverse City, and he agreed that it would indeed take care of the issue.  After removing the protective underbelly from the rig, Diana and I took it in to have the work done. 

The recommended solution addresses the problem from both sides of the frame.  On the outside, an angled piece of steel is welded over the frame, as seen below.

That piece re-establishes the integrity of the I-beam.  Note that Ace skip-welded, so as to not compromise the original beam with a continuous weld.  Lippert called for one long weld, and most welders will tell you that’s not a good idea.

The other part of the fix is what prevents it from happening again:

Ace ran three 2″ square tubes across the trailer, one between each leaf spring mount.  They also put in triangular gussets extending up onto the I-beam frame and down onto each spring mount as far as possible.  Kudos to Pat at Ace for the excellent welding job.  To boot, he had us in and out in one day!  🙂

While we were there, Pat showed me a travel trailer he was working on.  Instead of a true I-beam like we have on our Colorado, it had a 6″ assembled I-beam, made by welding three pieces of metal together in the shape of an “I”.  There were very few cross supports, and there were NONE near the wheels.  The frame had twisted to a point that the axles weren’t in alignment anymore.  He was doing the same sort of repair as he was doing on ours, so I knew from the start that he knew his stuff.  

When we returned to the campground, I nosed around beneath several different rigs to see if I saw the same issues.  The ones I looked at were different brands than ours, and Lippert had welded an additional piece on an angle to the I-beam at the spring mount.  Here is a photo of a 2005 Montana fifth wheel in our storage area:

There are several other brands of fifth wheels near us with the same setup.  While this piece of steel protects the I-beam from flexing, it really doesn’t protect the spring mount itself from twisting.  The square tube and triangular gussets that are now on our Colorado will take care of that.  If you are looking at your own trailer for signs of cracking, make sure the spring mounts are in good shape.  We also have an additional piece of “C” channel welded into each of our spring mounts (compare the last two photos) which offers some additional support at that point. I also noticed the heavy amount of rust on this unit. It appears it wasn’t powder-coated, or it spent time near salt water. 

Also, while I had the underbelly removed, I noticed that the manufacturer had run the trailer wiring loosely through the crossbeams:

That orange cable is our main power cable, and it had been rubbing on the top edge of a piece of angle iron.  It had not worn through, but it could have eventually.  I taped it and then bundled wires together with zip ties.  I also cut pieces of foam pipe insulation to fit over the angle iron.

When we returned home from Ace, I painted the steel with a Rustoleum primer, followed by a Rustoleum automotive grade paint.  I then reinstalled the underbelly.  The piece between the wheels hadn’t come out intact, so I purchased some plastic wall panels from the local home center to fashion new panels for that area.

I caulked and bolted those in, and I used expandable foam around the larger gaps near the spring mounts.  Total cost of the project, with welding, panels, foam and caulk:  less than $800.  Hopefully, we should be good to go for several more years.

As I stated earlier, we made a conscious decision to get a mid level fifth wheel as our first fulltiming unit. We still are confident that we made a good choice for us, as we have a decent rig for a fraction of the cost of an upper end RV.  Who knows what direction we will move in the future, but for now…we are happy campers!