So my truck has a bad jerk at 45-65 whenever the torque converter is locked up in OD or third. I feel like it could be a bad plug/coil, but it idle fine and the only symptom is the jerk or slipping feeling. Could this be a bad torque converter? Any help is appreciated.

 

I got the same issue and I don't think its the plugs or COPS because mine have less than 2000 miles on them. I just added some transmission goo to see if it helps before I do a fluid swap and so far it hasn't changed a thing.

 

Most likely a missfire. Torque converter locks and puts a load on the engine. Give it some fuel and take the load off and no more missfire.

 

Mine did it too....ended up being burned electrode on #6 plug...hope this helps, and gives you somewhere to start