That thrust plate is mentioned in a TSB, my 88 transmission had a problem with it as well. It was way too soft and when it pounded out it not only let the main shaft move back an forth it allowed the counter shaft to loosen.

That change was made in the Starion... Probably back in 84 or so. The needle bearing counter shafts failed very easily. Once you fix the plate problem you have a pretty strong transmission.

Definatly worth getting the better part from the dealer. Also shimming the counter shaft to zero clearance seems to help.

I machined up a spacer for the main shaft that also engauges the snap ring for even more support.

Kevin