Qsv1000

vehicle 2002 Camaro SS with 408 stroker installed and nitrous

Had a gearbox rebuilt and upgraded a few of the hard components, sun gear and installed 5 pinion planetary gear. Raybestos frictions and steels
Also installed a transgo 4l60 shift kit.

Just installed a TCI torque converter with stall value of +- 3600

Here are the issues now:

Gears are changing early in rev range then continuing to change up to 4th then stick in 4th. When revs drop it won't engage lower gears.

Only when you come to a complete stop and change from D to N then back to D will it then engage from 1st gear.

If you come to a complete stop in D it will just remain in 4th.

Is there something I can check on valve body or is it a rpm pickup issue or gear programming needing to be altered due to changing torque converter.

Any help much appreciated

Qsv1000

what can I do to get the box to come back through the gears on deceleration?

bbond105

Did the trans do this before the rebuild? Have you hooded up some kind of scanner to check off codes?

mrvedit

Very strange symptoms...
I cannot imagine how the trans can get stuck in 4th.
As bbond105 mentions, you will need to hook up a scanner that can command gear changes and see if the trans responds to commands.
Next, hooking up a trans pressure gauge will ensure that pressures are in the correct range for Park/Neutral, Reverse and Drive, and respond to blips of the throttle.