Transmission went Dead?

Hello I was happily driving my 2000 Toyota tundra over a sandy beach, just out of a blue, was driving in reverse for about 90 ft, and when I tried to shift forward, It just did'nt go. Any Shifts are gone, the transmission appear to be Neutralized. I can hear the engine relents changing only. There were no previous signs of slippery shifts, or delayed, nothing that would tell me in advance that the transmission was going bad.

First thing I did was change the Filter for a new one, and add new oil. I can tell that the old oil was pretty old and black.

Check some sensors and they are ok.

I unplugged both of the lines that comes to the Transmission fluid cooler, and there is no pressure or circulation of oil at all.

I uploaded a video 30 seconds before the fail appeared.
https://youtube.com/shorts/3_vrOL1PqnQ?si=SgaGqx8kLelERA9J

Can anybody comment any guess?
Than you.

 

First, we need to make sure that your trans is actually in gear. You could have an issue with the shifter level (common) where it's so sloppy that it won't go into a gear.
More info can be found here: Column shifter becoming sloppy | Toyota Tundra Forum and here: 1st gen shifter replacement prep | Toyota Tundra Forum

Second, if you do in fact have a bad trans, you'll want to ready through this info: A340E/F INFO DUMP | Toyota Tundra Forum

 

The Shift gear appears to be working,
ignore the oil spilling, I spill some oil when refilling the transmission.

https://youtu.be/KvFPpxZ2G5k?si=H8OJddYs3J7Ge2iT

 

You'll need to download a copy of the Field Service Manual and follow the diagnostic flow chart starting on page 1368

One of these is most likely your culprit

 

You never need to change the transmission filter in these trucks.

You never need to drop the transmission pan in these trucks, unless you're replacing a solenoid or something.

Have you verified if the driveshaft is spinning when in gear and pressing the gas? To know if your rear diff gave out, maybe?

Have you verified the fluid is at the correct level? Note: Follow the procedure in the manual, to read the correct section of the dipstick (hot/cold) and only read on level ground.

 

Thank you for your answers, I'll keep checking.