Labor, when stopped in traffic and transmission heats up, what is happening your transmission
Is in gear and your foot is on the brake waiting for light to change. The torque converter is
Being held back by vehicle foot brake and is in a stalled out mode which in turn is heating up the
transmission fluid. This is normal but may I suggest a long light shift on neutral where you
would not stall the torque converter. Dave Atherton Retired CAT mechanic