Clutch Point Changed Overnight

I'd been having trouble getting my '09 5speed into gear for a few weeks, with 1st and 2nd having a notchy feeling and usually requiring a lot of force, even at a dead stop for several seconds. I tried changing the shifter bushing with the replacement from Marlin Crawler and changed the fluid to Redline MT90, as both are often recommended around here. At first there was no change, but after a few days the issue started to go away, almost as if the new fluid had to work itself it.

The truck was shifting as good as ever for a couple days, plenty smooth in and out of every gear, when literally overnight my clutch point changed to the pedal at the floor. I couldn't shift into any gear without shutting the engine off, and the truck would start moving with the clutch barely off the floor, whereas it's always been in the dead middle of the pedal throw.

I've now replaced the clutch master, slave, and generously bled the whole system, including the slave, with no change. Adjusting the master cylinder to the point of virtually no pedal freeplay (wrong, I know), the engagement point is barely off the bottom of the pedal, just enough to shift into gear with the engine running, but still with a notchy feel.

I'm stumped, short of dropping the transmission to get eyes on the fork/throwout bearing/clutch. I'm curious if anyone thinks I might be missing something obvious, or if there's a common failure mode somewhere in the clutch assembly that I should look for.

Any thoughts/help appreciated

 

the truck is 10 years old
10 years old is end of life expectancy for automotive components

system must be bled with a pressure bleeder
the pedal can be adjusted

I'd like to think nothing internal to the transmission went out,
and rather clutch system, with makes sense to be worn at this time.
Especially after narrowing it down considering the other parts you replaced, as part of the diagnostic process to rule them out of the equation, as well as replacing tired old parts.
That is however, assuming you chose quality parts, and did correct work (pressure bleed); some folks don't. Incorrect work and shitty parts cause issues.

Maybe there is some bending fatigue or broken finger(s) going on with the pressure plate not allowing it to release and change gear.

 

Sounds like you've already replaced the hydraulics and are confident the system is bled correctly. Look at the throw distance of the slave cylinder and clutch fork, if it's moving a normal amount of distance and the engagement point is still on the carpet, then the problem has to be inside the clutch unit.

for example the pressure plate release fingers will get weak and bent. So even though the release bearing is pushing them down, the plate never fully hinges and let's go of the disc.

You shouldn't need a fancy pressure bleeder to bleed a toyota clutch line. Looking at the throw of the slave cylinder will tell you what you need to know

 

Issues with pp diaphragm arms, TO bearing or fork. Think the trans is going to have to come off to figure it out. Might be able to get a borescope in there via the fork hole to see what is wrong.