Astro van from 1995 with a 4L60E transmission.

Some time ago I replaced 3 solenoids (Torque converter clutch solenoid, shift solenoids A-1-2/3-4 and Solenoid B-2/3 shift) in the transmission – because I had an error code 83. - but the change didn't eliminate the error code.

Van was running - but not 100% optimal – it then started to had a bad idle etc. – so my focus was on the engine – so I changed TPS sensor, tried with another PCM (no good) , changed the idle air sensor and the distributor – now the engine runs really fine.

At the tumbling around with the van - I thought, why not also changed the 3-2 control solenoid in the transmission to get rid of that error code? - so did that and also changed the Oil and oil filter in the transmission. – filled 3 liters on it (thought it could take 4.7 liters) – but overfilled it according to the dipstick.

Got 1½ liter sucked out and it’s now 3 mm above the hot marker field at the dipstick.

But it still has trouble - error code 83 still there and:

It shifts from 1-2 without any problems
The shift from 3-4 are “slippery” and it won’t get in Overdrive.
It shifts into 4th but a couple seconds afterwards the rpm's start going up and it act's like it would like to go back in 3 - It still pulls, but acts like it is slipping.

If I’m driving 60 mph and makes a “kick down” the RPMs increases, but it won’t shift from 4-3 immediately.

It is possible that there is something wrong with the torque converter (no lock up) and if so - should it throw a error code beside the code 83? -

Any suggestions what might be wrong?