08 5R110 issue??

[Biggsw784]

I have a buddy that has a 08 and he said that it shutters when he takes off and all the u joints and carrier bearing are good. he said that it shifts crazy when he gets on it hard too. he also claims that it doesnt do it when he puts it in 4wd. he is running a spartan on a 275. any ideas?? could he be the torque converter?? thanks

[WildStyle]

What does it do when he returns to stock power levels?

[04hdfatboy]

I would bet axel wrap. Traction bars should help.