I was getting on my car pretty good the other night on the interstate. I hit redline and shifted from 3rd to 4th. When I hit redline in 4th, I went to shift to 5th and the shifter wouldn't move. There was no play at all, it was pretty much locked solid. I let off the gas and played with the rpms and after about 30 seconds, it came out of 4th. Now, whenever I shift into 3rd, I get a grinding. It also got stuck one more time in 4th. Can anyone advise what might be wrong? I have the '89 GT listed in the signature with a T-5. Thanks in advance!