Manual trans: Can shift into gear when truck is off, but not when it's running.

What would cause this?

Truck not running: I can push the clutch in and I can put it into any gear I want.

I start the truck up (in neutral, clutch in). No issues turning it over and making it run. It's just that when I go to shift it into 1st (or any gear for that matter), the shifter doesn't budge. There is too much resistance.

 

Sounds like the clutch pedal is not truly disengaging the trans from the engine.

Can you crawl under the truck & have someone press the pedal while you inspect?

Good luck
Following for solution

 

Look for a bent or broken Clutch pedal bracket or clutch fork.

What happens when you crank the Truck in gear with the clutch pedal pushed in?

The Truck tries to move?? Starts fine?

 

I think it might be vandalism. Caught someone on the security cameras lingering around and under my truck. Might be someone in the area.

Someone mind checking out these pics I took? Does anything look out of place?

#1 is from under driver side, looking up towards the cab floor/transmission.

#2 & #3 are from under driver side, looking towards the front of the truck and at the clutch fluid lines connecting to the transmission.

 

No visible vandalism there, and no leak on the slave cylinder. How is the fluid level in the reservoir? Any leak past the seal into the cab, around the pushrod to the pedal?

Otherwise, as has been said, you need to see movement of the slave cylinder and fork when the pedal is depressed. If not you may have a clutch master cylinder failure, or pedal bracket problem. About 3/4 to 1” movement is normal, IIRC.


Pull the rubber boot around the fork back and check that the pivot ball and mating socket on the fork are OK, and not broken off or worn through.

And as said, look up to where the pedals pivot, it’s not an uncommon issue for the bracket on older pickups, and I’m pretty sure 1st gen tacos too.

 

Unless you have enemies about the only reason to crawl under the truck is to steal the cats

as for shifting I guess they could remove your slave cylinder or cut the hydraulic line then you would see a puddle .

 

Seems like a worn clutch disc or bent fork tho rare. Did the pedal start to get high in the past few weeks when driving? If so clutch is suspect. Disc or fork trans needs to come out for diag

 

maybe

 

Slave cylinders go out every so often. Sounds like the clutch isn't properly disengaging.

 

I’ve had two instances of this issue in the past, albeit with non-Tacoma manual transmissions. Both times it was throw out bearing related.

Mine is a very small sample size. Check the operation of the slave and master to ensure everything is working there.

There should be a travel length listed for the clutch from pedal depressed to released. If this is in check, you know the problem is past the clutch fork in the system.

 

There is also a like a lag bolt/hydraulic shaft the peddle uses up underneath the clutch peddle to adjust free play.

 

Sounds like the clutch hydraulics have failed. Replace the master and slave cylinders. It's a cheap and easy job to do yourself. Get the Aisin brand parts from Rock Auto.

 

As others have stated, the clutch isn't disengaging. First, check toe play (1/4"- 5/8"), I prefer it on the lower end. Then have someone depress the clutch pedal while you watch the clutch fork move (engine off). Should be about 1" travel. If much less, I would bleed the system, just to eliminate an air issue. If you have trouble bleeding the system (at the slave bleeder valve) the clutch master cylinder has gone bad. If you get good pressure out of the slave bleeder when bleeding then the slave has gone bad. That will isolate the problem but if it's MC or slave, I would replace both.