Trans balked at 4-5 upshift on track, "Shakey clutch" in paddock ???

[Joesurf79]

So...yesterday on track, towards the end of the last 20 min. run session, I suddenly had the transmission almost refuse to upshift to 4th. Almost like there was a wall in front of 4th. With a little pressure, there was a 'click' feeling and it went into 4th - but the shifter travel didn't feel like it was full travel if that's possible? It seemed to hold onto 4th just fine, until I needed to shift to 5th. There weren't any symptoms leading up to it, just all of a sudden on this lap - no dice on a smooth shift to 4th. The 4th - 5th upshift felt super notchy as well. Shifting at 7,100 ish rpm for both upshifts. (4.56 rear end gears mean I have to use 5th at 3 spots on this track). The subsequent 5-4-3 downshift felt normal, but it felt like my normal blip-downshift into 3rd wasn't smooth as it normally is, which might have been me or might have been related to the situation? There was fresh transmission oil (amsoil 75-90 synthetic) in the gearbox. Ambient temps up around 92F.

Drove two laps like this, and pitted - the phenomenon wasn't in my head, it was real. Creeping through hot pits and back to the paddock, the clutch felt "shakey" if that's a thing? I let the car cool down, and then before putting it on the trailer I drove it a bit. 1-2-3 shifts zipping around the paddock felt okay in the gearbox, but the clutch was still "shakey" / grabby. Pulling on the trailer there was some clutch smell (I'm assuming) that I had never smelled.

Given the smells and clutch feel, I'm 99% sure it's toast, but I need to know if there is a way to diagnose gearbox health with it out of the car, short of complete teardown? I'd hate to put it back in to find that it's toasted as well. Is it possible that the clutch dying could make 3-4 and 4-5 upshifts hard on track near redline? If that's the culprit, then maybe my trans is still usable?

Any similar experiences, opinions, appreciated. Also, any recommendations on a new clutch / flywheel for track use at N/A power levels is appreciated - never had a clutch die before in a car.
Thanks!
Joe V

[Joesurf79]

Got it all apart! Even managed to keep all my fingers Everything from the back of the crank has been removed. I have more questions now, and I'm hoping the track junkies can help me find the answers

1) throw out bearing pics attached. Pretty sure it died, but that's based on it having bunch of play, sounding rattle-y, and having puked all of its grease inside the bellhousing. I don't have the new one yet to compare to, so I'm not sure how to tell if it was the culprit. Thoughts?

2) the clutch wear plate has a bunch of wear material left before the rivets! Not sure how thick is considered minimum tolerance but I'm betting it would still be usable. The damper springs and surrounding areas are all heat-blued. Is that normal? The pressure plate spring teeth look okay to me...thoughts?

3) the input shaft to the trans had a little play in it. Is that normal? Not looking to measure it to the thousandth, but is it an "any play is bad" situation?

4) there's an aluminum quill over the input shaft that the TOB rides on (thanks for the warning mkarr !!) Which is pretty gacked up. I have a new one on hand which I plan to grease sparingly. Any recommendations on what type of grease to use?

Thanks again MKarr for the helpful tips. If the new clutch had gotten here in time I'd be testing it by tomorow. Sigh...UPS delay