brenark
04-19-06, 08:16 PM
I have a 1996 deville with the N* engine and drive-line; 121000 miles. I have been having an intermittent problem with a "shudder" during transmission up-shifts. It doesn't happen on every up shift, only intermittently. It normally occurs at about 28 mph and sometimes in the mid 30 mph. I think it is most frequent going from 3rd gear to 4th gear. It never happens going from 1st to 2nd. The "shudder" lasts for about 0.5 seconds. I can hear it and also feel it in the floorboard and through the accelerator pedal. It only happens after the car has warmed up and only happens when the transmssion upshifts. The "shudder" sounds and feels like the traction control has come on, but it is not as loud or as severe. I turned the traction control off with the button in the glove compartment. That did not help. The "shudder" does not occur with aggressive throttle or WOT. The transmission shifts very smoothly with aggressive or WOT. It only happens when I feather the gas pedal and the tranmission shifts at 28 mph or in the mid 30 mph and mostly in the 3rd to 4th gear shift. Other than the "shudder" the transmission and engine is very smooth.
I have read through as many threads trying to find someone with a similar problem, but have had no luck. The "shudder" is very faint, but noticeable. It never happens at the torque converter engage/disengage speed of 42 mph. The torque converter comes on a goes off without any noise. Above 42 mph I lightly tapped the brake while watching the tachometer and I can see the engine speed change, but I don't feel or hear anything abnormal.
I had the motor and transmission mounts checked by my dealer and they are fine. The dealer could not explain the "shudder" and told me that it was so faint that I shouldn't worry about it. However, I will need new front and rear struts and plan to put on the passive Boston Suspension, but I would prefer not to spend $500+ until I understand what is causing the "shudder".
I have read about problematic transmission solenoids, but could find anyone describing problems similar to what I am having as a cause for replacing the solenoids.
Does anyone have any ideas? Any input would be greatly appreciated. By the way, I checked the DTC codes. No active or history codes of any kind.
I have read through as many threads trying to find someone with a similar problem, but have had no luck. The "shudder" is very faint, but noticeable. It never happens at the torque converter engage/disengage speed of 42 mph. The torque converter comes on a goes off without any noise. Above 42 mph I lightly tapped the brake while watching the tachometer and I can see the engine speed change, but I don't feel or hear anything abnormal.
I had the motor and transmission mounts checked by my dealer and they are fine. The dealer could not explain the "shudder" and told me that it was so faint that I shouldn't worry about it. However, I will need new front and rear struts and plan to put on the passive Boston Suspension, but I would prefer not to spend $500+ until I understand what is causing the "shudder".
I have read about problematic transmission solenoids, but could find anyone describing problems similar to what I am having as a cause for replacing the solenoids.
Does anyone have any ideas? Any input would be greatly appreciated. By the way, I checked the DTC codes. No active or history codes of any kind.