Transmission slipping

I have an 07 tacoma v6 doublecab 4x4 auto. 54,000 mi. It started slipping so I decided to check the fluid level per the trans posts on here. 4 Qts low! WTF It has no leaks anywhere, no extra fluid in the transfer case, and its not in the cooling system. Im at a total loss. I was a auto tranny mech 35 yrs ago and Im stumped. It still slips in 1-2 and 2-3. Any ideas?

 

The fluid had to go somewhere ?
Was the trans serviced and they didnt fill it up ?
Sounds like you are too late now . Forward , intermediate and direct clutch is burnt

 

No service has been done. Im really not too fond of the closed system of these units. Yea im thinking its toast. Its been a long time since I tore into one of these. Anything electronic that can go bad? I just dont know where the fluid went other than where I stated.

 

I agree that the trans without a dipstick is a real bummer . The fluid level is often overlooked because of this so called sealed unit .

Here is the diagnostics http://freepdfz.com/pdf/ba750e-b-and-a750f-bautomatic-b-btransmission-b-3220218.html

There is electrical components that can go bad . Sounds like your issue is more mechanical .

I think I have all the overhaul manuals in PDF .

 

Thanks for the info. I will read thru it a little later. Need to get out and split some wood.