Shakes in gear at a light . I've replaced ('cause I want to keep it ) entire front end (control arms, tie rods ,knuckles , rotors pads , sway bar bushes ,etc.) EGR Valve and Modulator and 5 different fuel cleaners , but not CR502 or any oil additives . After all that it still shakes .
Shakes in gear at a light
If you put in park and it stops the shake, odds are that the torque converter is on its way.
It can also be a vacuum leak possibly a misfire caused by bad fuel injector, spark plugs wires coil/ distributor. Bad catalytic converter, clog fuel filter , failing fuel pump, faulty o2 sensor. Put in park like YASER said. If it stops shaking then look into the torque converter. If it still happens start with looking for a vacuum leak first then move down the list of possible causes
Also check your motor and trans mounts