do new and old trucks shift the same?

I will say the most consistent thus far have been the two t680 that I have been in. The best in terms of shifting was easily the 2015 Peterbilt 579 with the 13 speed Eaton. I almost got one when I was looking to buy a truck. It just had a few too many issues starting out and could have become a bigger money trap than necessary.

 

An old 15 speed with 10th against the dash always shifted smooth to me,usually with a million or better. My 10 speed fuller eatln with 650k shifts smooth, always has. I've never shifted a Rockwell trans smoothly , they always scratch. The key is knowing the rpm drop between gears and shifting in a timely manner.

 

How do you grind an automatic?

 

I'm sure someone can figure it out. Nothing is foolproof, to a sufficiently talented fool.