There are times when cruising between 45 -60 mph, transmission in o/d. I attempt to give it slightly more throttle (not a big stomp on the pedal but slight pressure) and the transmission gives a big car-shaking shudder (like a manual would in 5th gear at 10 mph).
It seems like it's lugging and not shifting out of o/d when more power is called for. The car is secondhand to me, but I do know that the tranny was replaced 30K ago.

Is there a kickdown adjustment for this? Simple as new tranny fluid? I can't help but think this is doing damage to the transmission with each shudder.

Ideas? Thanks.

 

changing the fluid could help...also check to see if its filled to the proper level....