Overstuffed
New member
- Joined
- Jun 29, 2025
- Messages
- 3
- Reaction score
- 1
- Points
- 1
New member here. 2012 Sierra crew cab, 5.3 gas. Intermittently, I’ll be driving about 35 mph and when I accelerate just fast enough for it to shift without hitting passing gear, I get a really hard shift into what seems like a lower gear. Crazy thing is, no codes are tripped in the transmission. I’ve been to a very good transmission guy and of course, it shifted fine for him. Any idea what’s causing this?