I drove a MAN tractor back in the day. 4 wheel steering and 8 wheel drive. You used the clutch to start and stop but not to change gears. This one was part of the Ground Launched Cruise Missile system, pulling a TEL (Transporter Erector Launcher) of 4 cruise missiles. That thing had some torque!
Heres what it looks like firing. Thankfully we never had to fire ours!!!!