TC Locking and Unlocking, causing vibration

[ajfrac]

OK, have a 05 f350 SRW that i just bought with 156,000 miles. thought it was just stiff suspension but its feeling more and more like a vibration. this is all with no load btw.

havent narrowed specific speeds yet, but around 50-70 ish, when not going downhill, it feels like the TC is locking and unlocking every second, causing it to vibrate, almost like its getting little power boosts and popping forward just a bit. I push the tow/haul and it downshifts and the vibration seems to dissapear for the most part. I will try to relearn the transmission tomorrow, but i have a feeling that wont fix it.

any insight?
thanks

[drewmeister13]

Get an edge insight. Their is a PID for gear selection and tc lock/unlock. This will for sure tell you if it is locking and unlocking. Also the insight is great for monitoring deltas, boost , egt if you get another probe.