I'm a UPS driver and typically like to ask the local mechanic the problems with vehicles I write up and what not. However, we will be losing all our diesels soon and this problem won't be addressed.
I was driving a cummins with an Allison 1000 (has about 505k miles on the chassis). As I was going along the transmission refused to shift out of third, yet at some point suddenly downshifted into second where it was stuck at for a good 15 miles. After red lining the engine for about 20 minutes i made it to my first delivery. Popped it into reverse, the transmission sounded like it exploded while also rocking me to oblivion. The same happened again when I put into drive after that, yet had no ot



