Harry S Evansville , IN April 30, 2016 Appliance: General Electric General Electric GTDP180ED0WW Ge Dryer Gtdp180ed0ww / : Timer knob was cracked and would not engage the switch. How to replace Timer Knob. I had already pulled the old knob off by hand, so all I had to do was line the the knob up with the shaft and push on. Done. It took longer to open the packaging than it did to install the knob. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes