Won't go into gear when engine is running

02 Taco 2.4 2wd.

just drove the truck on a 3 hour trip the other week and then did a little around town ride the other day. (It's not my daily)

when I went to get into it today now it will not go into gear when the engine is running. If I turn the truck off it goes in just fine. If I look under the truck while pressing the clutch I can see it moving the shift fork (or whatever it's called) on the trans that goes to the clutch. I'M STUMPED!!

any help would be greatly appreciated

 

When's the last time you changed your transmission fluid and did you use high quality GL-IV fluid like Redline MT-90?

How old is the clutch?

Have you checked your shifter seat and pivot cup?

Have you adjusted your clutch pedal rod?

 

Is the fluid in the clutch master cylinder black ?

 

Clutch was replaced like 3 years ago but have only put like 2k miles on it since. All factory fluid was put in it. Fluid looks in glare at shape still. Shifter seat and cup were replaced a while back.

 

Nope. Not really even dark yet.

 

how much free play in your clutch pedal?
Is this all gears?

 

No free play. And it's in all gears

 

Check the clutch bracket and firewall for cracks.

While the slave cylinder moves the clutch fork or the pivot may have cracked or broken. Causing the clutch release bearing to not contact the clutch plate.

Did you notice anything different before you parked the truck?

 

Nah. Everything seemed normal. I don't see any cracking or any flexing of the firewall. ‍♂️

 

When my clutch hydraulics went bad I had the same problem. The slave cylinder would move, but not far enough to release the clutch. I'd replace both master and slave cylinders.

 

If you put it in gear while it’s not running then try to start it with the clutch pushed in will the truck try to move? Another culprit is the clutch fork itself cracking and flexing. It may look like it’s working from the outside put it’ll flex enough if cracked that it won’t release the clutch.