My brother and I were driving the other day and normal driving conditions, we had been on the highway a few hours and we came to a merge and I think the transmission dropped down into overdrive and it started bucking and shuddering. So we weren't sure what it was all I really cared about was getting home. It only did this on low rpms tho, once the foot was put into it, everything was normal. What could this be?
either your torque converter is shuddering. Simple fix...Add " Dr instant shudder fix" from nappa auto or on ebay ect. Put the 2oz bottle into your transmission dip stick tube. it will be gone. OR one of your plugs is missfiring.
I have a similar problem with my 94 lightning. It shudders between 30 and 40 mph when you are accelerating from 1500 to 2000 rpm in 3rd gear. Im looking into solutions for this as well. I just changed my plugs and wires so it shouldnt be that. Could be a timing issue as well. Might be worth looking into. I'll definitely look into the torque converter for mine.