I seem to be having a little issue with my truck, it's a 2006 5.7 with 103k. Sometimes while driving on the highway and the torque converter locks up the truck will shudder, but this doesn't always happen maybe once a day or once a week. So is my torque converter going, or is it something else? Thanks in advance for any help.

 

When is the last time the fluid was changed? Wouldn't hurt to flush the fluid and change the filters.
It's not the MDS kicking in and out is it?

 

Changed the transmission fluid about 3k ago hoping it would solve the problem, but it didn't. At what speed is the MDS disabled?

 

did you check your ujoints ?.. had a shudder and thats what it was

 

MDS can work at any speed depending on throttle position and engine load. You can try driving in tow/haul mode. It will lock out 5th gear but also disable the MDS.