3rd Gen Automatic Transmission Fluid Level Check DIY

Do you pin the trans. fluid thermostat open and did you bypass the radiator? I'm going to try that before I spend another C note and a half day installation time to try a different brand cooler. As I said, I can't physically go with any larger cooler and the cooler I have is definitely removing heat from the fluid. The difference between the inlet temp. and the discharge temp. is significant and unmistakable.


I really don't see a significant lowering of temps. on the ScanGauge now as opposed to prior to installing the cooler.

 

Honestly,. Glad I'm not alone lol.

 

QUOTE="Illini Tacoma, post: 25886902, member: 354145"]Do you pin the trans. fluid thermostat open and did you bypass the radiator? I'm going to try that before I spend another C note and a half day installation time to try a different brand cooler. As I said, I can't physically go with any larger cooler and the cooler I have is definitely removing heat from the fluid. The difference between the inlet temp. and the discharge temp. is significant and unmistakable.


I really don't see a significant lowering of temps. on the ScanGauge now as opposed to prior to installing the cooler.[/QUOTE]

yes I have the thermostat pinned open. Did not bypass anything - the Hayden is in series with the directional flow of the system.


Ignore the big hose and pump housing in the middle of the pic - that is the cooling pump /hose for my SC unit. The hose coming from the oem tow package cooler (hose connection closest to the passenger side on the bottom of the oem tow cooler shown in the pic) is connected to the top inlet of the Hayden cooler. The bottom discharge connection from the Hayden cooler is connected to the oem connection for the return to the transmission (this is the top hose connection going into the radiator from which the original system connected the tow cooler back to the transmission return flow).

NOTE: There are lots of pics and information available on the 3rd Gen Forum under the thread "3rd gen transmission Cooler Upgrade." I run the

$59 Hayden 679 Universal 11” Rapid-Cool Add-On Transmission Cooler to Enhance Cooling (not for direct replacement of the factory unit)

Hayden 679 unit. Check it out.

 

yes I have the thermostat pinned open. Did not bypass anything - the Hayden is in series with the directional flow of the system.


Ignore the big hose and pump housing in the middle of the pic - that is the cooling pump /hose for my SC unit. The hose coming from the oem tow package cooler (hose connection closest to the passenger side on the bottom of the oem tow cooler shown in the pic) is connected to the top inlet of the Hayden cooler. The bottom discharge connection from the Hayden cooler is connected to the oem connection for the return to the transmission (this is the top hose connection going into the radiator from which the original system connected the tow cooler back to the transmission return flow).

NOTE: There are lots of pics and information available on the 3rd Gen Forum under the thread "3rd gen transmission Cooler Upgrade." I run the

$59 Hayden 679 Universal 11” Rapid-Cool Add-On Transmission Cooler to Enhance Cooling (not for direct replacement of the factory unit)

Hayden 679 unit. Check it out.[/QUOTE]


Interesting. I pulled my OEM completely. Probably another factor.

 

I've finally gotten around to topping off my trans. fluid following the installation of our trans. fluid cooler. This method of checking the fluid level is without a doubt the silliest piece of engineering an auto maker could possibly come up with. Those of us who have experience with just warming the transmission up and pulling a dipstick find this to be a colossal waste of time and fluid (at $13 potatoes a quart we don't want to waste too much fluid but it takes a minimum of 1 qt.).

The only rational motive for this nonsense is to give Toyota stealer/dealers yet another way to dive into owners pockets who either don't want to, or can't do this BS for themselves. I have a feeling the vast majority are paying someone to do it.

Rant over.

 

Just completed my first drain and fill at 45K miles. I have a 2016 Tacoma OR access cab.

some notes:

you must absolutely push the thermostat shaft in to perform this procedure properly if equipped.

I drained approx 2500mL of old fluid. And added 3000mL (3qts) into the system.

I followed the obd2 procedure as described. The transmission fluid heats up super fast so the “D” was blinking until I realized I should just let the car cool down completely. I actually started the process 30 minutes after returning from running some errands so it’s better to start work on a cold car.

while at proper level check temp the overflow gave up surprising little, maybe 150-200mL before going to a trickle. This actually supports the many claims that the 3ed gen Tacoma’s shipped about 0.5Qt low and I sure as hell hope 45k on the clock while slightly under filled did not do any damage


Here’s a link to the relevant manual sections:
www.ttguide.net/adjustment-932.html

 

Know it's a few years old, but this is the post I keep coming back to when explaining what needs to be done for this job. So stinking simple and well done!

 

Nowhere in the Toyota's procedures says to pin the thermostat.
I had to wait hours to drop tranny from normal temp of 190 to below 95.

 

That’s why I am bringing it up. That’s a canned Toyota procedure for trucks. I spoke to a number of reliable techs and for these vehicles the thermostat must be pinned.

 

Where’s the transmission dipstick lol. This has to be the worst engineering decision ever on my beloved Tacoma.

 

Truth!^^^^^^

It's beyond a bad engineering decision, it's stupid.

 

Then your realible tech friends should be able to hook you up with the procedure. This one is from TIS and ain't have a word "thermostat" in it.

 

I may be missing something about your great writeup right up, so my question is, I don't understand why you need to add a qt of trans fluid before starting the fluid level check procedure, only to possibly have all or part of the qt come pouring out of the overfill hole, as I would think that once you've gone thru the procedure and you remove the overfill plug and if you get a little dribble of fluid coming out your good to go, and if not, you then pump trans fluid into the fill plug until it does.

 

Need to check the level at specific temperature.(accurately). I suppose you could warm the fluid to the required temp and try to put it in in running tranny with the fill plug removed while navigating around a hot exhaust

 

I went underneath my truck today, and it was quickly evident that trying to add trans fluid to a fully heated up exhaust was something that I probably wouldn't want to attempt, so I can see the rationale for adding trans fluid prior to starting the level check procedure.

 

i wonder if you could just shape a U shaped dipstick with a longer side and read how close it is to the over flow tube top. after performing the procedure on a cold trans to get an idea of where it needs to be without having to do the heating procedure....

if im understanding the procedure correctly trans temp is just a way to get the correct amount of fluid in the trans.

 

I recently purchased a 2021 Tacoma. Decided I should inspect the transmission to see whether it was low from the factory. I decided I should pull the overflow plug when the transmission was cold and had sat overnight, just to get a baseline of what the level was cold, and when I pulled the overflow plug in the AM 1.5 quarts came out of the overflow plug. I pumped 1.5 quarts back into the transmission, and didn’t bother do anything else because I assumed if 1.5 quarts came out of the overflow plug after it had sat overnight then I wasn’t low on transmission fluid. Am I right in assuming the level is above the filled mark and I don’t have to worry about my transmission being low on fluid?

 

I'm not sure but that doesn't sound right to me

 

Follow the procedures...temp check mode, engine running, etc.
Your cold baseline idea is fucking things up.

 

It would have been to easy to fill to overflow tube either hot or cold with motor not running..