Trans not shifting properly-2005 F350 Diesel

[billt]

2005 F350 Diesel - less than 30,000 miles
At times it does not shift at all. Sometimes it will shift very late. Makes a "rubbing" sound when letting off the gas. Occasionally makes the "rubbing" sound in between the times it decides to shift. Almost like it is staying in overdrive or tow mode. No codes or warning icons appear on the instrument cluster.

Thanks in advance for your help. By the way, I suspect that I am the least mechanically inclined of any members of this forum.

 

[blacksnapon]

2005 F350 Diesel - less than 30,000 miles
At times it does not shift at all. Sometimes it will shift very late. Makes a "rubbing" sound when letting off the gas. Occasionally makes the "rubbing" sound in between the times it decides to shift. Almost like it is staying in overdrive or tow mode. No codes or warning icons appear on the instrument cluster.

Thanks in advance for your help. By the way, I suspect that I am the least mechanically inclined of any members of this forum.

You'll have something electronic going on. Scanning for codes will be the first step. That "rubbing" noise I would bet is the infamous "turbo fart". It shows when you let off of the accelerator.