i've got an 03' duramax with allison trans 300,000 mile. it shifts rough but only on the shift from park into gear or from drive to reverse. is there anything other than a rebuild that i can do?
Welcome,
Yes, the slip joint in the driveline can make the shift from N to D or R feel bad or a real jerk. With the 300000 on the truck this could be worn. Also u-joints could add to this.