4 low won’t engage

Hello. I am having an issue with the 4 low not engaging. 4 hi works just fine. It’s a manual transmission and I’d prefer not to burn up the clutch when I need to go slowly up a rocky hill or to climb over stuff. I’ve tried all the “tricks” I’ve come across on here, searched the internet, YouTube, and nothing works. Any ideas on where to start looking under the truck?

 

To enter/exit 4Low
Vehicle Speed must be below 3MPH
Clutch must be fully depressed (M/T)
Transmission must be in Neutral (A/T)

https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

When in doubt remove the transfer case limit switches and clean them. Make sure the little ball detents press in and out freely as transfer case lubricant can gun them up over time. Reinstall and it could help.

 

Well. While doing a service on it last night I noticed the fluid in the clutch reservoir was low. Close to an inch below the Min line. After filling it and completing the service I went for a test drive. Went to a dirt lot and tried “standing” on it. I was lifting myself out of the seat with the pressure I was applying to the clutch pedal. And…it worked! Went right in to 4low!
Thank you all for your suggestions!

 

Glad you got it working, but the issue had nothing to do with the fluid level. There is a little button switch that the pedal lever presses when all the way down, that's the switch that the computer looks for to allow you to shift into 4lo. If you're having to stomp down on the pedal that hard, you're beating on your master cylinder and need to adjust the switch position to where it engages just at the bottom of the natural pedal travel. Should be able to adjust it by screwing/unscrewing the nuts that hold it in its mount.

 

This. You shouldn't have to literally stand on the thing. Time for some adjustment, and also look into why you were so low on fluid. Check for leaking up near the clutch pedal both inside and out, check you lines, check the slave, and if V6, check the accumulator (and then remove it lol).

 

Adjustment has been made. Wasn’t aware that button was even there! No longer need to press the clutch down so hard. Not sure about the fluid level. I can’t find any leaks. I guess I assumed the mechanics at the dealership were checking it. I had been using my local Toyota dealership for service due to not enough room in the garage to pull the truck all the way in. And winters in Wyoming are not the best time to do an oil change in the driveway. Garage problem fixed. Back to doing it myself.
Thanks again for all the info and advice!