M5OD sticking in 4th - Is this the problem? (video)

[Mass]

I may have overlooked something when I rebuilt it a few weeks ago.
Can someone with manual experience tell me by looking at the video if the 3rd-4th slider is too loose?

2006 2.3 2wd
has 300,000 miles on it and decided to rebuild while I had it out for a clutch. It was starting to get a slight noise in 5th on long drives and figured bearings were worn.
Here's what I did:
- I replaced ALL bearings.
- Replaced shifter bushings
- Replaced stub shaft grommet
- Freeze plugged the shift rail holes
- Left the synchros alone. They all looked perfect anyway but the only place that had the fiber lined ones wanted like $900. f that.
- Replaced 1-2 slider and hub
- Replaced 5th reverse slider and hub
- Replaced reverse gear
- All seals
- Properly shimmed the input bearing
- Left shift forks alone because they only have cosmetic wear. You can just barely feel it running your fingernail across it the wear surface.
- Left the original 3rd 4th slider and hub like an idiot
I swear the slider didn't feel that bad when I had it torn down which is why I didn't replace it but now it looks pretty bad compared to the ones I replaced.
Could this be why it's getting stuck in 4th?
Several times the past few days it would get stuck in 4th and wont come out till I pull the shifter stub and "reset" the rails with a screw driver.

 

[Mass]

I should mention all shifting functions were normal before the rebuild and about 500 miles after rebuild. Then all of a sudden out of nowhere I can't drive more than a few minutes without it happening.

 

[Shran]

I don't know if that's what's causing that issue... weird. Did you replace the springs and keys on that hub? FYI I had the same question about one I rebuilt a while back, had the opposite problem, wouldn't stay in gear, I was told that this amount of movement is normal:

The M5OD manual I have doesn't say much about this, it just says to inspect problem gears, shift rails and forks and synchronizer, or could be a loose shift fork (check for broken pin or selector plate.)

I rebuilt a FM-145 and the manual for that said the hub springs MUST be installed so that the open ends of the springs are facing in opposite directions but doesn't say why. I assume that it's to create even pressure outwards on the hub keys. I don't know if that applies to the M5OD but it would seem logical in my mind that it would be a good practice.

It's super weird that you can get it out of gear with a screwdriver and not the shifter itself.

 

[Mass]

Thanks for the reply Shran,
Looks like the same amount of play as mine. so weird...
That's a good theory. I seem to remember the springs only had 1 hole to "hold" in on each side of the hub. So I feel like it's idiot proof but then again I've been known to test the laws of idiot proofing so idk.
I went ahead and ordered a new 3-4 hub with new springs and keys today. I feel like I need to pull it apart and recheck everything anyway. I'll def. check the spring location when I do so.
What is the selector plate? I'll have time to at least check the shift cover out again tomorrow.

The screwdriver thing is crazy. Really wish I pulled the stub and immediately put it back in to see if it would shift. Maybe by pulling it out it unbound itself or something.
Could a worn stub shaft cause it?