when i'm coming to a stop, the car shudders and jerks forward as if i was constantly on and off the brake. it does not do it when i come to a stop while in neutral, only when it is in drive. then when my car downshifts from third (doesnt do it when in 2nd), it makes a big clunk. please help me out. the car idles fine. i replaced the tranny mount with an energy suspension poly piece but it didnt help. could it be the torque arm?

 

TCC solenoid is plugged or stuck on. Or the convertor clutch valve in the pump may be sticking.