Tread beam expansion

This started happening suddenly with the tires in my mod about 3 months back and I have messed around with the tire values many times and can't seem to track down this bug. Rarely, a tires tread beams (I think) suddenly expand to ~x2 their original width, which causes dramatic bouncing and flying around. Tire values seem stable otherwise. Below is the pressurewheels section of one of them (There are a few dozen of various sizes but most of the values are the same). All wheels are slightly less narrow than rim. Any ideas appreciated.

Code:

    "pressureWheels": [
        ["name","hubGroup","group","node1:","node2:","nodeS","nodeArm:","wheelDir"],
        {"disableMeshBreaking":false,"disableHubMeshBreaking":false},
        {"hasTire":true},
        {"enableTireReinfBeams":false},
        {"enableTireLbeams":true},
        {"enableTireSideReinfBeams":false},
        {"enableTreadReinfBeams":true},
        {"enableTirePeripheryReinfBeams":true},


        //general settings
        {"radius":0.332},
        {"tireWidth":0.17},

        //tire options
        {"wheelSideBeamSpring":0,"wheelSideBeamDamp":15},
        {"wheelSideBeamSpringExpansion":401000,"wheelSideBeamDampExpansion":25},
        {"wheelSideTransitionZone":0.06,"wheelSideBeamPrecompression":0.98},

        {"wheelReinfBeamSpring":21000,"wheelReinfBeamDamp":160},
        {"wheelReinfBeamDampCutoffHz":500,"wheelReinfBeamPrecompression":0.99},

        {"wheelTreadBeamSpring":221000,"wheelTreadBeamDamp":60},
        {"wheelTreadBeamDampCutoffHz":500,"wheelTreadBeamPrecompression":0.99},

        {"wheelTreadReinfBeamSpring":101000,"wheelTreadReinfBeamDamp":60},
        {"wheelTreadReinfBeamDampCutoffHz":500,"wheelTreadReinfBeamPrecompression":0.99},

        {"wheelPeripheryBeamSpring":121000,"wheelPeripheryBeamDamp":25},
        {"wheelPeripheryBeamDampCutoffHz":500,"wheelPeripheryBeamPrecompression":0.98},

        {"wheelPeripheryReinfBeamSpring":121000,"wheelPeripheryReinfBeamDamp":25},
        {"wheelPeripheryReinfBeamDampCutoffHz":500,"wheelPeripheryReinfBeamPrecompression":1.0},

        //general tire values
        {"nodeWeight":0.32},
        {"nodeMaterial":"|NM_RUBBER"},
        {"triangleCollision":false},
        {"pressurePSI":"$tirepressure_F"},
        {"dragCoef":5},

        //groundmodel friction multipliers
        {"frictionCoef":1.15},
        {"slidingFrictionCoef":1.0},
        {"treadCoef":1.0},


        //advanced friction values
        {"noLoadCoef":1.41},
        {"loadSensitivitySlope":0.00017}
        {"fullLoadCoef":0.5},
        {"softnessCoef":0.7},

        //deform values
        {"wheelSideBeamDeform":15000,"wheelSideBeamStrength":80000},
        {"wheelReinfBeamDeform":101000,"wheelReinfBeamStrength":101000},
        {"wheelTreadBeamDeform":15000,"wheelTreadBeamStrength":32000},
        {"wheelTreadReinfBeamDeform":15000,"wheelTreadReinfBeamStrength":30000},
        {"wheelPeripheryBeamDeform":101000,"wheelPeripheryBeamStrength":101000},

 

TTT

 

Could you also paste the code above '"pressureWheels": ['?

 

Not the exact same tire but here's one of them, they all pretty much look like this.

Code:

"RDP_F_forklift_1": {
    "information":{
        "authors":"BeamNG",
        "name":"25'' Forklift Tires",
        "value":115,
    },
    "slotType" : "tire_RDP_F_7S",
    "flexbodies": [
        ["mesh", "[group]:", "nonFlexMaterials"],
        ["forklift_25", ["wheel_FR","tire_FR"], [], {"pos":{"x":-0.50, "y":0.0, "z":0.0}, "rot":{"x":0, "y":0, "z":180}, "scale":{"x":1, "y":1, "z":1}}],
        ["forklift_25", ["wheel_FL","tire_FL"], [], {"pos":{"x": 0.50, "y":0.0, "z":0.0}, "rot":{"x":0, "y":0, "z":0}, "scale":{"x":1, "y":1, "z":1}}],
    ],
    "variables": [
        ["name", "type", "unit", "category", "default", "min", "max", "title", "description"]
        ["$tirepressure_F", "range", "psi", "Wheels", 28, 0, 50, "Tire Pressure", "Relative to atmospheric pressure", {"subCategory":"Front"}]
    ],