Failed vertical frame 3" X 3" posts 2005 Signature

[Daytonaman]

Started this thread years back, when my posts cracked 02' Sig
Mine had been welded before.
Mine had the 1/2x 36"gussets.
These pulled away and didn't hold.
Former owner had them welded on before, said "it will happen again"
I found having them "rewelded" weakened them and they cracked again.
They held for awhile till I could figure out how to properly repair them.
I visiited Alliance Coach where they had done these on many RR10's.
The tech who did this repair was very helpful.
He told me they inserted a a heavy wall 2x2 into the 3x3 posts.
He said 2x2 is a loose fit into the 3x3 posts
They shim the 2x2 with 1/8 x 1 strips for a tight fit.

After hearing all this, I looked again at how the 3x3 posts are attached.
They go all the way to the top of the frame.
So I made a wood jig to slip into the 3x3 all the way up.
I took the jig to a welding shop and duplicated it using 2x2 HW square.
I made 1/2x 36 gussets and ran them up to the frame all the way upto the floor
This was most important as other coaches I looked at did not have gussets attached to frame rails.

[Bussinit]

Thanks for the info. How did they repair the outside if the 3x3 post once the insert was welded in? Aside from the gusset did they do a fish plate or just weld the crack together?

[slemnah]

Originally Posted by Daytonaman

Started this thread years back, when my posts cracked 02' Sig

Mine had been welded before.

Mine had the 1/2x 36"gussets.

These pulled away and didn't hold.

Former owner had them welded on before, said "it will happen again"

I found having them "rewelded" weakened them and they cracked again.

They held for awhile till I could figure out how to properly repair them.

I visiited Alliance Coach where they had done these on many RR10's.

The tech who did this repair was very helpful.

He told me they inserted a a heavy wall 2x2 into the 3x3 posts.

He said 2x2 is a loose fit into the 3x3 posts

They shim the 2x2 with 1/8 x 1 strips for a tight fit.



After hearing all this, I looked again at how the 3x3 posts are attached.

They go all the way to the top of the frame.

So I made a wood jig to slip into the 3x3 all the way up.

I took the jig to a welding shop and duplicated it using 2x2 HW square.

I made 1/2x 36 gussets and ran them up to the frame all the way upto the floor

This was most important as other coaches I looked at did not have gussets attached to frame rails.

Any pictures?

[Daytonaman]

Sorry, no pix, lost them in a failed phone memory.

The inserts are interference fit; welded at the bottom
Inserts had to be shimmed because the 3x3 posts are seam welded internally and are in the way of an exact fit.
Everything was re-welded at the failure areas.
The worry was a coach floor fire, and some arc welding electrical damage.
20,000 mi and solid.
No alignment necessary as everything just went back together as it was built.
There other ways to repair this, but I did it the way Alliance suggested.

Discovered the cracks when I raised the rear bags to the max. Clunk!
Also the "X" braces crack off at the top of the frame rails.

[Bussinit]

Thanks everyone for your replies. I got it fixed. I told them everything I learned here and on other forums/threads. They ended up fixing the break with a v-joint, they also inserted a solid steel bar into the tube, drilled four holes into the tube and welded the steel bar to the tube through the holes. They finished it off with a 3/8" gusset along the rear of the tube.