Allison transmission shudder 4th to 5th gear! Any thoughts?

Big ~O~ · January 26, 2017

Hey Guys. I'm having a bad shudder in the transmission when shifting from 4th to 5th gear only. Not happening all the time though and only occurs when driving on an incline, never on the flat. Some shudders appear worse then others even when driving on the same roads. One day it was so bad that my little guy said "Dad I think the truck is going to blow up"!! So far I've counted 13 times that it has happened. The other issue is that the truck seems to surge ahead when downshifting to first gear just before coming to a complete stop. Again not all the time. Brought it to the dealer and they couldn't get the truck to duplicate my complaint and it wasn't tossing any codes. Of course the very next morning after I pick it up it would do it twice...unreal! They told me to keep an eye on it and pop back to the dealer so they can take another look. I hope this is not any indication of how this truck is going to be. Only 11,000 km on the truck. So disappointed right now. Anyone have any thoughts or ideas? Thx!