Wondering if anybody has had any issues at cruising speeds between 60-70km. Trans was just completely rebuilt and when cruising anywhere between 60-70 kph when it is in 5th at 1500 rpm it keeps surging from 1500-1800rpm. It feels like it is going in and out of lock up. The trans guys are saying that with the scanner on it, everything is working properly whatever the tcm is telling the trans to do it is. They are lost and can't figure it out? I told them it wasn't like that before.

Anybody have any ideas?? Thanks in advance