Don't do this.....Inside the valve spool, there is a torque bar, that is designed only to turn the valve to divert oil to one side or the other. When the oil is taken out of the system, the torque bar then is taking the full load of the feed back from the rack. This load normally is taken by the piston. The resulting feedback will not be controlled by the torque bar, and will twist it back and forth, possibly breaking at some stage. So it requires the locking of the top part of the shaft, to the lower part of the shaft. Do not weld it..... they are hardened components, that need to be heat treated correctly for welding. Go and see an expert rack modifier......they will machine a top splined part from 4340....or take your chances....
Don't do this.....Inside the valve spool, there is a torque bar, that is designed only to turn the valve to divert oil to one side or the other. When the oil is taken out of the system, the torque bar then is taking the full load of the feed back from the rack. This load normally is taken by the piston. The resulting feedback will not be controlled by the torque bar, and will twist it back and forth, possibly breaking at some stage. So it requires the locking of the top part of the shaft, to the lower part of the shaft. Do not weld it..... they are hardened components, that need to be heat treated correctly for welding. Go and see an expert rack modifier......they will machine a top splined part from 4340....or take your chances....