I just recently swapped the transmission on my car it’s 6mt and I was having problems with it not going into gear so I decided to get a new transmission, replaced it and it did the same thing, my mechanic adjusted the clutch all the way out and it worked perfectly fine it was gliding through gears like butter, I changed the slave cylinder and it went back to how it was before I put on back the old slave and it still does not let me put it in gear(bled the clutch both times) I ran out of ideas and I think it might be the master but don’t know, I need help ASAP

 

Almost guarantee it's the CMC.

If you have more than 100k on a vehicle, or when you change the clutch, you should ALWAYS replace/rebuild the CMC, CSC, and replace all the fluid.

The rebuild kits for the OEM CMC/CSC are less than $50 for the pair.

https://www.z1motorsports.com/clutch...it-p-9662.html

https://www.z1motorsports.com/clutch...de-p-9651.html

You can visually watch the throw on the CSC and see if it's not pushing far enough.

 

I changed the clutch master cylinder and the slave cylinder bled it until it had no bubbles, it sounds like it might need a new clutch but I just installed a stage 3 clutch not so long ago like 3 months ago or less, I’m out of ideas at this point

 

Did you bench bleed the master cylinder or is there air inside it?

Also, the early year G35 came with a stamped steel clutch fork that's prone to bending. You should get the vehicle up in the air and visually inspect the clutch arm being actuated while someone else presses on the pedal to see how much throw it has.

Why are you using a stage 3 clutch? 500 HP turbo build?