GT80 Shifting Trouble

[sir_switch]

I have a 1979 GT80 that will not downshift (stuck in 4th gear). The clutch and shift lever seem fine. I need to know what my next should be. I'm hoping that I can correct this without having to drop the engine and split the case. Any advice/tips would be appreciated.

 

[Patman]

Sounds like a bound up shift fork. Have you tried rocking it back and forth a bit to see if it will pop loose?