Hey all, this is my first post for help on the form, so please let me know if I should change anything with my post.

I have some knowledge when it comes to Cummins engines, but I am a pretty novice with auto transmissions and tuning general.

To start, I bought my truck already deleted and tuned.

The previous owner had his buddy in a small town shop do the tuning, so I have no idea how good it is.

The truck runs and drives fine, but the shifting is pretty harsh.

It sometimes jumps around a bit after a shift, it's completely random and fairly rare when it does, but the biggest problem is that when the 68RFE is shifting from 2nd to 1st when coming to a stop, the transmission will stick in neutral.

If you start to slow to about 10 mph and hit the pedal, it will just free rev.

Then the CEL will come on with a gear ratio error.

Shut the truck off and open the door, and put it in drive, and you are good to go again.

The strange thing is, if I use the gear selector to tell it to shift to first at about 8 mph, it will do that no problem.

Then put it back in drive, and off you go.

There is more shift flare between 1st and 2nd than any other shift.

I am not sure if this is tuning related or valve body or the whole transmission is toast.

If I totally come to a stop-in drive, sometime, it will find 1st but with an aggressive clunk and the truck's lurch.

Did anyone hear of this?

I have changed the fluid, the filters, the input and output speed sensors, the pressure sensor, and the solenoid pack with no change.

Thanks for any help or experience anyone has!