Won't go into 5th
 

I'm having an issue with the tranny not going into 5th. When i go to shit into 5th the shifter just starts vibrating. Even if I try to force it, it doesn't go into 5th. I tried backing out the screw on my pro5.0, but that hasn't helped. I thought I backed it out enough, but maybe I haven't. I got the tranny off another board member, and have not been able to get into 5th since i installed it. He said the day before he took the tranny out of his car, he was able to go into every gear. Any suggestions. Should I try backing the screw out more?

sounds like you have syncro or slider gear problems to me.

i don't see how unscrewing the stop on your shifter is gonna help, if it allows you to go into the other gears.

he prob missed 3rd and hit 5th and fried something in trans.

I agree with fitz98t. If it were a clutch problem I hear reverse is the gear that you won't be able to go in. Search can't go into 6th and you'll see I had this same problem. Eventually cost $1300 for the rebuild which took about 8-10 days. Drive it untill you can afford it though, because the rebuild price isn't going to change much. Only a 100 bucks if you have to change out the gear. You don't need 5th anyway. You have your overdrive for highway and you should get through the quarter with 4 gears.

There's also a very common problem with these F-Body T-56s where the mainshaft and the 5/6 drive gear are only splined for half the length of the gear. It can begin to allow the 5/6 gear to rock on the shaft, making it hard to get into 5th and, eventually, impossible. This happened to my trans, albeit after 105K miles. Getting into every other gear was no problem, but 5th was impossible. Unfortunately, the only fix is a new mainshaft and 5/6 drive gear.

6th gear has no problems at all. 6th gear works perfect. Im not worried about the 1/4 right now, cuz the car doesn't go there but once or twice a year. I worried about daily driving.

Call six speed inc and tell them your problem. They will be able to tell you what needs to be done to fix it.