I have 92 SC with 124K miles. Took it in to a shop for coolant flush, brake fluid exchange, tranny flush and fuel system cleaner. Tranny was working perfectly at the time. I picked it up and had no 4th gear. Works perfectly in 1, 2, 3 and Reverse. Checked plastic fittings for accelerator linkage near carb and they seem solid. Any chance they could look ok and still be bad? Also, tranny fluid was over filled. Has anyone had any experience like this? Does anyone have any suggestions as to what I should do? Would appreciate any help available. Thanks