Hello, and welcome to Just Answer.
Please allow me to assist my esteemed colleague Mike C...
If your Tundra does NOT have a dipstick, it has what Toyota calls "WS", or "World-Specification" transmission fluid.
This fluid is NOT meant to be changed at the 'normal' intervals; nor is the filter. Actually, there is no filter, Toyota transmissions utilize very fine mesh 'screens". They run about $200.00 each.
With that being said, and IF the fluid needed to be replaced (as if the transmission developed a leak, and was repaired), there is a VERY specific procedure that must be followed.
First, the engine/transmission needs to be within a very narrow temperature 'window". This requires the use of a scan tool that is capable of measuring the temperatures. WIthout it, you cannot perform the task. The correct fill level is determined at a very specific temperature.
Second, a special tool is utilized to introduce the new fluid into the transmission, again, if you do not have the tool, the task cannot be performed. Adding too much fluid, or not having enough fluid can and will damage your transmission. Trust us.
If I were you, and you really need to have the ATF level adjusted, leave it to your dealer.
If HE does not perform the proper fill procedure, HE will be responsible for buying you a new transmission...and, at about 5 grand for a replacement, it is in the dealer's best interests to do the job correctly.
We are sorry that this is not the advice you were seeking, but, to ignore the factory-specific procedure will result in a failed transmission...It is not worth it to try this yourself, unless you have the correct tools.
Thanks for choosing Just Answer.
Opinion: I see that you have opened this question again and my fellow colleague Peter has answered you. I fully agree with his statements.
You need to understand that trying to change the ATF, for whatever reason, without the special tools, is going to DAMAGE your transmission.
You have two of Just Answer's best Toyota Technicians advising you the same thing. Trust us. We do NOT want to see you have to buy a transmission.
Edited by Toyota Service on 10/27/2009 at 12:08 AM EST