They are also known for converter failureMine did that - but it is a Diesel - however the shudder is usually bad trans fluid or partially clogged pan filter contributing to causing low line pressure . Have you changed it recently - mine did this when I put in synthetic trans fluid. I then put in a can of Seafoam Trans Tune, it got really much better and acrtually stopped, then I dropped the pan and turned up the force motor one quarter turn - and refilled with fresh old school straight petroleum trans fluid - and because I have a line pressure gauge permanently connected - it raised my running line pressure to around 100 unless I stomp it and then goes slightly higher and holds tight. 1-2 shift is a bit crisp - but not enough to notice. At idle it still goes to 40 to 45. The force motor part is known as the epc solenoid a Borg Warner 50080 Transmission Solenoid Electronic Pressure Control (epc). I am pretty sure if fits 1991 and up.