I pulled the T5 from my project Mustang to figure out my 5th gear problems. 5th gear doesn't feel like it's fully engaging. The parts guy is recommending a new 5th gear, synchro assembly, and bronze fork pads which all sounds good with the worn teeth on 5th. My concern is that new fork pads might not clean up the noticeable play in the shaft upon which the fork is mounted. Playing with it in my bench, when the play is at the extreme, 5th doesn't fully engage. This matches what I felt when driving it.
How do I clean up the play so that I don't have future issues? When I get home I will double check that there are pads on the fork but, I believe I verified their presence. By all appearances, this is the recent rebuild that the PO claims and I have no reason to not believe him thus far.
(I'm going to edit with the link I posted in my project thread) Here it is, very short but illustrates my issue https://youtu.be/Ws4oST6k7EM
I have worked on a number of T5's and none of them have a shaft that moves as much as that one. What limits the movement of that shaft is the hole in the back of the trans case the shaft passes through. It's not a close tolerance hole but it does limit movement. What does the hole in your case look like as I can't tell from the short video?
I was shocked to see the movement of your 5th gear shifter fork, but I watched other videos and see almost as much movement. After some image searches I finally found a good picture of the inside of the tail housing and I see that it's actually supported in a pocket in the tail housing. So one end of the 5th gear shifter shaft is supported inside the main case and the other end is supported inside the tail housing. For that reason, you couldn't really measure lateral movement of the 5th gear shifter shaft and fork without installing the tail housing (at least temporarily).
From your video I can't actually see a shift pad on the end of the fork that I can see near the end of the video.
Lack of shift pads would introduce lots of slop in the shifting process.
Thank you both for the replies. I had some help in realizing that the tailhousing secures the other end of that rail but, it is very good to have confirmation. There are 2 new fork pads, white plastic, on each shift fork, 5th included. As I mentioned in my project thread, where I went into more detail, the parts guy (Bruce at thegearbox.com) is recommending a new 5th gear to replace the broken teeth, a new synchro assembly, and bronze fork pads that fit a little tighter than the plastic ones.
I think that I must have messed it up at the track, jamming it into gear without realizing that the clutch wasn't all the way in, or something. Possibly related to reverse being unsynchronized which is why the new-to-me old T5 trick is to shift to 4th before reverse to at least get it spinning.