diff --git a/VECTO/GUI/IEPCForm.vb b/VECTO/GUI/IEPCForm.vb
index eedc20a6ea900fd04323ae9a5015ee8e1a0ae22d..813e992f2995855e3bf3d079c36c53e12e88a300 100644
--- a/VECTO/GUI/IEPCForm.vb
+++ b/VECTO/GUI/IEPCForm.vb
@@ -709,6 +709,10 @@ Public Class IEPCForm
 
 	Private Sub cbDesignTypeWheelMotor_CheckedChanged(sender As Object, e As EventArgs) Handles cbDesignTypeWheelMotor.CheckedChanged
 		tbNumberOfDesignTypeWheelMotor.Enabled = cbDesignTypeWheelMotor.Checked
+		cbDifferentialIncluded.Enabled = Not cbDesignTypeWheelMotor.Checked
+		if (cbDesignTypeWheelMotor.Checked) then
+		    cbDifferentialIncluded.Checked = False
+		end if
 		If tbNumberOfDesignTypeWheelMotor.Enabled = False Then _
 			tbNumberOfDesignTypeWheelMotor.Text = "0"
 		Change()