Unsolved Barstow Roofsign

I am trying to make a simple roofsign for the barstow. I am having trouble keeping the nodes and beams from flying off into the air on impact with another object. It has 6 nodes in a triangle pattern. connected with beams between the 6 nodes. The roofsign mesh is just a square in the middle of the triangle. The bottom nodes of the triangle are connected to the r1, r2, r1ll, r1rr, r2ll, r2rr nodes on the roof of the barstow. I can get the sign to show with the mesh when the vehicles spawns and it appears to support the sign. When you drive into an object the beams break and the nodes fly off onto the ground. I cannot figure out why the roofsign breaks when you hit an object.

I have the beams set to the following:
{"beamSpring":2001000,"beamDamp":125},
{"beamDeform":8500,"beamStrength":"FLT_MAX"},
The nodes are set to:
"nodes": [

["id", "posX", "posY", "posZ"],
{"group":"barstow_roofsign_gd"},
{"collision":true}
{"selfCollision":false}
{"nodeMaterial":"|NM_METAL"},
{"frictionCoef":0.5},
{"nodeWeight":2.0},

 

Found the problem was with another part that did not have a closed breakgroup.