Just had a new 6.5 installed into my truck and drove it home and it drive just fine and was going into overdrive. This morning I go to drive the truck and its not going into overdrive now?? Another diesel tech said he thought that the trans was electronic and used the eletronic injection pump as a refence to shift?? Also the tach will now peg out now intermittingly?? Is this a symptom of anything you may know of?? Thanks for any help.