I recently bought a donor truck that I had taken parts off of including wire harness pcm tipm etc...transmission was in limp mode due to p0869 so I found that it was the pressure sensor so I changed it and the code went away and my reading was back to normal. I have thinkdiag scanner and am able to read quite a bit of data in the modules. I did a relearn once it was out of limp mode and now, from watching the scanner, it has 1st and 2nd but once it gets to 3rd it's like it applies neutral and it just revs up. But if I hit the gas pedal a bit harder at higher rpms 3rd will engage starting at like 4k rpm but it won't shift past 3rd. I bought a month's subscription for alldata and according to the quick learn procedure my clutch volume indexes are in the proper range. I ended up dropping the trans pan and valve body and got a new solenoid pack just because I thought it might help and in doing so I noticed one of the retainer bands holding what I think is the OD clutch in has shifted in its slot. One side of the band is maybe 2 inches out into the opening where it shouldn't be. Will it be okay if I tap that back in if it'll even go or is that effecting my shifting at all and if so and if it has to be pulled in order to fix that I'm just gonna throw a spare transmission I have in. BTW it's a 545rfe transmission. I will attach Pic of the retainer band I am talking about

 

From what I can see, The ports on the piston assy look really bad. You should have that piston replace. Since you have a 545RFE transmission. There are no bands to worry about. Since you also have the valve body out, Look at the side plate on the passenger side of the valve body, If those actuators fall out of the ports in the valve body, that will give you shifting problems too.

 

Okay I will work on that today I've never done trans work except helping a friend's neighbor do a swap on a Tahoe but I get the concept and I have a Haynes manual to get me through step by step...hopefully