Unfortunately, we can not check the control for this model controller.
I can only advise the following:
1. update wheel's device driver
2. In the setting of device (Control Panel -> Game Controllers -> Properties) set the mode: 2-axis (combined, ie the throttle pedal and brakes on same axis)
3. find user configuration file
It lies here: \My Documents\My Games\Clutch\ user_config.cfg
find in it a string
seta joy_axisThrottle ""and write in quoted right axis. This could be: "lX," lY "," lZ "," lRx "," lRy "," lRz "," rglSlider0 "," rglSlider1 "or even any axis (for different controllers differently).
Presumably for your model of controller a "rglSlider0" (again, there is no way to check

), that should have
seta joy_axisThrottle "rglSlider0"