Driving what seems to be an under maintained Rig

SMH…To make a truly long story short, I was just hired by a guy. I’m in a 2019 t680 with a 10-speed Eaton and a Cummins ISX15. I’m attempting to diagnose an issue. The trans feels like it’s binding up and releasing when it downshifts and clunks often when upshifting. The rpm drops to under 10000 every shift which lugs the motor through each gear. My thoughts is the air dryer or a trans pm but it seems kind of a simple/common issue? Video link below.



https://youtube.com/shorts/s0j-1rOQeLM?si=5kASWp1aTCX21Q2y

 

Why the u-bolt? That makes some sense because when accelerating I’m getting a motor mount type action where the engine seems to be lifting and as it shifts it falls and clunks 60% of the time depending on my throttle position but it seems I feel a binding action as if the driveshaft is twisting and releasing making the clunking noise while the rpm begins the gear at 9k which isn’t normal to me coming down from 15000?

What do you mean input? The input side of the transmission?

That was also a thought for me. The owner needs one and has suffered tremendously overworking the girl. Truck has 455 hp. What more could it need?


Thx for your answers. I was thinking that the air sound I’m hearing as the trans downshifts is a symptom as it’s a little unusual with the extra wheeze/whistle right before it downshifts. Also the abs failure at the end of the vid doesn’t happen normally but to probe; the video is of me getting the unit up to about 8th gear and letting the speed/downshifting happen on its own so the noises and the abs failure was a uncommon isolated event that has to have something to do with the issue. Has anyone had this issue!.

 

bobtail!