maybe it was all thwe wheels then it was so long ago.try replacing the whole "landing gear section with this.
[LeftMainGear]
SystemType=LANDING_GEAR
Retractable=FALSE
DragArea=0.00
ModelNodeName=Undercart L
ShockAnimationID=-1
ShockStroke=0.07
SpringFactor=1.3
DampingFactor=2.0
WheelNodeName=Wheel L
RotationAxis=X-Axis
RollingRadius=0.35
CastoringWheel=FALSE
RollingCoefficient=0.025
MaxLoadFactor=6.0
[RightMainGear]
SystemType=LANDING_GEAR
Retractable=FALSE
DragArea=0.00
ModelNodeName=Undercart R
ShockAnimationID=-1
ShockStroke=0.07
SpringFactor=1.3
DampingFactor=2.0
WheelNodeName=Wheel R
RotationAxis=X-Axis
RollingRadius=0.35
CastoringWheel=FALSE
RollingCoefficient=0.025
MaxLoadFactor=6.0
[TailGear]
SystemType=LANDING_GEAR
Retractable=FALSE
IsSkid=TRUE
HideGearNode=FALSE
ModelNodeName=Skid
ShockAnimationID=-1
ShockStroke=0.05
SpringFactor=1.3
DampingFactor=1.8
ContactPoint=0.0,-7.30,-0.53
RollingCoefficient=0.7
MaxLoadFactor=6.0