having an issue with what i think is the tranny but not sure....fluid level is fine but at high speeds ( 60 to 70 mph ) the car is shifting up and down ( almost like im manually puting it in to overdrive and taking it back out ) keep in mind it is staying in 4th and its not the tranny going into 3rd.....any helpers out there ?....speed sensor maybe ? doubt it but its all i can come up with.....thank you

 

Welcome to the forum,it sounds like your torque conterter is locking and unlocking.

 

is it fixable without having major tranny repairs?