How to Drain/Refill Automatic Transmission

I followed the O.P.s procedure. It is not that difficult. I found that it equals a 3 quart change for both of my 4.0s. Now when I do it, I meet the following conditions; Park on level concrete and allow to sit overnight. Without starting the vehicle, drain the transmission and refill with 3 quarts fluid. This make sense as the owners manual states to add up to 3 quarts, which would allow for the above procedure. I strongly recommend that you use the O.P.s procedure first. But from now on for me, it is the above procedure on both of my Toyota 4.0 transmissions. Also, I use Toyota fluid.

 

The procedure is the same (mostly), the 3rd gens temp check temperature is slightly different (95°F-113°F, I think.... I can verify with the FSM if you need me to) and you need to pin the transmission thermostat open to allow fluid to flow through the coolers to ensure you get the fluid level correct.

 

Are there any crush washers that need to be replaced on the drain, fill or over flow plugs when doing this procedure?

 

I did not replace any washers and did not have any issues.

 

Same here, I've reused mine several times without issue as well. But just incase you want/need them...

 

Hey thanks!

 

Heyo, new member here, so sorry if I've skipped over this.
I drive a 3rd Gen 2WD and am attempting to simply check the fluid level out of fear that it's low. Not noticing any symptoms, but wanted to make sure for peace of mind.
I followed the OPs instructions as far as the wiring ODB and whatnot. I get a series of blinking ABS, traction, and airbag lights. I know for sure that I don't have a "AT TEMP" light in my cluster, so I'm lost on how to know its in the correct mode. I notice no new blinking lights at all after the shift sequence described in the OP. If its already been covered, I apologize, and feel free to route me to the correct page in the thread.

Thanks in advance

 

Why can't you leave the engine running while you ad fluid to the transmission? Can't you slowly ad it until it trickles out of the overflow hole with the engine running?

 

Sure I could. But according to the OP, the fluid has to be at a specific temp before that would give me an accurate reading of my fluid level. I can't figure out how to get it into/tell if its in temp check mode.

 

The procedure in this thread was specific to 2nd gen Tacomas. I am not sure it directly applies to the 3rd gen, although I haven't read through all the posts. Procedure for topping off should be similar, but not sure the temperature specs are even the same. Maybe someone with those specs can chime in.

I have a ScanGauge II that I used on my 2nd gen -- but I need to see if the 3rd gen temp comes through on the same PID as 2nd gen, haven't tried it just yet. Probably should check my fluid level as well . . . but would like the temp specs.

 

Does anyone know if I would be able to tell the transmission temp using a scanner tool instead of using the light on the dash? I was thinking of picking up a code reader to have just Incase

 

Yes, my post right above yours mentions one -- the ScanGauge II. I think the UltraGuage can do it as well. I know with the ScanGauge you have to program it in, but you can find the parameters using the Google.

 

What about a generic code reader? I was going to pick one up to use for all my vehicles

 

I have two scanners, a cheapy autozone and a fancier one. Neither show ATF temp, but I believe I can pay extra to install software on the fancier unit. I just use an IR gun to read the temp. It has been shown to be just as accurate. I've used it on wife's Lexus and my Taco.

 

Probably not, it's not stored like codes. Codes are stored in the ECM and read out. You need something that can sniff on the vehicle's CAN bus network while it is running. ScanGauge and UltraGauge tap into that stream of data. Many parameters are "standard," but transmission fluid temp is not. You have to tell the scanner what data packet ID's you want to sniff on, which is why I had to program mine. Not hard, just have to enter a few codes in.

An IR gun will probably get you close enough -- if the outside of the pan is at the low temp point, the fluid is likely sitting in the correct range, or at least close enough that it's not going to make much of a difference in the resulting fluid level.

 

I’m about to do a drain and fill just waiting on the atf to arrive in the mail. My plan is to measure what comes out and put the same amount in. I was going to do this with the trasmission at operating temp like when changing engine oil. That’s when I started researching thermal expansion of atf and concluded that I would need to let the atf I drain out reach ambient temperature before using it to determine how much to put back in. I didn’t read every single post but didn’t see this mentioned. I will likely just drain it at ambient temp now to avoid waiting for the drained fluid to cool.

 

After you drain and fill be sure to check that you have the correct amount of transmission fluid.​

 

Yes as mentioned above, just make sure you check the capacity with the atf at the proper temp. that will confirm the proper level.

 

Not having any problems but I just can’t leave all of that old fluid in there. Will probably end up doing the whole “check trans temp” procedure but at the very least I’ll still be at the same level that I started with. I’m also curious about really how critical the temp is. I understand that there is thermal expansion of the atf from ambient to normal operating temp and that it’s supposed to be between two specific temps but is there anything other than a temperture reading going on when the truck is in the “check trans temp” mode? This could be a good excuse to buy a scan gauge or something similar that reads trans temp if all I need to know is atf temperture when removing the plug to see if anything comes out.

 

Before you do anything, you should practice a few times with jumping the 4 &13 pin with a wire. It is really easy to do, and if that’s the only thing you needed a scan gauge for, well you just saved some money. As far as how critical the temp for the atf is. It’s so easy to check the right way and be safe vs.
an expensive repair.