Transmission Drain and Fill???

Well, I've read just about every thread on here about a transmission drain and fill in addition to watching about 30 videos. My 2018 Runner just clicked over 81,000 miles and I'm guessing it's time, but I'm really nervous about doing this. I know how to turn a wrench, change my own oil, have my own tools, etc. but I've never done this and don't want to screw up my trans. Anybody got their thoughts to share or tips or warnings on how not to screw my Runner up if I'm going to do this?

 

Biggest tip is dont get distracted while you are working. Lately, it seems like that’s been my biggest issue that leads to dumb mistakes.

 

It seems pretty straightforward -- from what I've seen if you've got a scanner (I just bought an OBD MX+), everything else is easier. But you don't know what you don't know. And yeah, distractions, for real. Where'd that bolt go?

 

It's really not that difficult or hard to do. Everything is accessible. Most important is having a way to read the trans temp. I used the Torque app, found the equations online for the pan temp and got a $20 Bluetooth obd reader on Amazon. That was the hardest part.

Cut the top off an old gallon container and mark it in quarts. Drain into that container. Refill trans with the drained volume plus 0.5 to 1.0 quart extra. Let it sit and idle, run it through the gears a couple times. The take a nap underneath until it gets to temp (I forget what it is, maybe 100 to 120F). Remove the overflow plug until fluid stops pouring out, then replace the plug. Done.

 

Take it to a shop and have it done correctly with a transfer device. Drain and fills are a waste of time.

 

What are the equations for the pan temp? I haven't heard of that yet.

 

If you're using an app, you need the PID and equation for it to read. For the trans pan temp I used the following:

PID 2182

((((A*256)+B)*(7/100)-400)/10)

Min temp -40
Max temp 350

 

Wow, thanks for that. I thought there would just be a transmission temp gauge on the app - haven't had a chance to play with it yet.

 

Def spend a few minutes playing with the app, making sure you connect and it reads. Don't want to find issues there when it's game time.

 

This will be controversial but this is what I did.....

Drain while cold (1st thing in the morning before starting).

Measure the amount you drained.

Fill with the same amount.

Done.

 

looks like the OBDMX+ has an A/T Transmission Temp1 and Temp 2 under the extra options for Toyota, Lexus, and Scion -- I'm assuming that one is for the pan and the other for the converter (maybe not the right term)?

Nimby, you ever have any issues doing it that way?

 

So what if you were low on fluid before you drained any?
Not a good way to do this IMHO, you're taking a big expensive risk of damaging your transmission.

Do it right so you can sleep at night!

 

This is what I did at 92k. I forget the trans capacity, but OEM fluid is $13-$15 a quart. I ended up paying maybe $80-$100 more than if I'd done it myself.

 

I just changed my transmission oil on my 2018 TRD 0ff Road at 36,500. I did a complete flush/filter change using the transmission pump. I removed the return line, pumping out 2 quarts at a time and installed two quarts. I bought a $15 sprayer at Home Depot, cut off the tip and installed a flexible clear hose, to install the two quarts and fill the pan. Worked perfect, but took awhile to complete. Just ordered oil to do the transfer case and diff's. Being 5 years old I am working on replacing brake fluid and cooling fluid also. I had all the steps listed on paper, used the truck OBD to get the correct temp on trans oil and tried the steps before doing the change. I had no problems. I agree with McSpazatron, pay attention and don't get distracted.

 

I used “Car Scanner” app and did not need to input any equations. But to tell you the truth, all the apps made me feel things were a bit hacked. Always felt like if they were wrong, I’d have no way to tell.

That’s why it’s good to spend time playing with them. Make sure the numbers at least make reasonable sense. Mount it up to your dash and watch how they increase and decrease. The post torque-conv temp will increase almost immediately whenever the torque converter slips, whereas the pan temp will move up and down more slowly. Make sure everything makes sense. Then, when the pan temp is at the “check temp”, touch the pan. If you get burned, throw that damn app in the garbage lol. It really should not be that hot (very low 100s if I recall, dont quote me).

When you have it running, remember it comes up to “check temp” pretty quickly. I really didnt have that much time to cycle the gears since it was summer out and I had driven it earlier the day I changed my fluid.

Ultimately, it’s really hard for me to see how the volume of oil will change all that much by being off on the “check temp” a little bit. It’s basically supposed to be a little hotter than a warm summer day.

 

Nope!

 

Well, I figure it's lasted 80,000 miles with the same fluid level, so........

 

Same! I'm pretty sure you remember my post about shooting the piston out of a brake caliper last week, lol.

 

I usually like to do my own wrenching, but I decided this particular task wasn't something that I wanted to deal with. I just called my local dealer, and they said that that's something that they could do. I think it cost me around 200 bucks.

I forget what the price of the full flush would have been, that was a drain and fill. The first dealer I called kept insisting that the fluid didn't need to be changed, and it wouldn't give me a price when I asked for a drain and fill.

I bought mine around 79k, I had this done at 105k. I'm at 146k now, probably have it done again in another 20 or 30k. I do mostly highway driving, I'm easy on the transmission and everything.

 

Everything I’ve ever read sys that power “flushing” an older trans is a bad idea as it can stir up sediment that then may clog the narrow valve body passages. Lots of anecdotal stories online of old transmissions that never had regular changes and then they do a flush and it causes problems.

Anyway, if you want to really change all the fluid it can still be done at home, you just need to repeat the drain/fill a couple times with a few days driving in between.

the procedure isn’t really hard once you figure out the method to check trans temp. I did it on my 2nd gen Tacoma once (same trans?) and there was a trick to get the trans light on the dash come on at the required temp… not sure if there is a similar procedure on the 4R but her than that the rest is no harder than a diff change.

 

Oh yes I do. I could only shake my head in full sympathy at the situation lol

 

I just drain and replace with same amount. Done

 

Did everyone just forget that theres another 4runner site that been around for years longer with a ton of useful info??

Do not just do this with the trans cold @Sleestaks. There is absolutely more than one right way to do this job and also a TON of wrong ways... please see below. All stems from this posting which is arguably one of the best single threads on DIY checks for 5th gens, and I dont have a 5th gen

 

Thanks for that @iamincrediboy I have definitely bookmarked that page -- I'm getting more comfortable with the idea of doing it myself now that I've played around with my new OBDlink MX+ and have created a full engine/transmission temperature dashboard with Engine Temp, Engine Oil Temp, A/T Temp 1 (pan I think), A/T Temp 2 (converter), Engine RPM

 

That’s the way to do it. Get comfortable with your OBDII app for reading the pan and converter temperatures so you can set the fluid level properly.

For adding the fluid I used a length of 3/8 inch ID tubing plugged into the fill hole, routed into the engine compartment with a funnel and supported with tie-wraps away from hot and moving parts. This makes it easy to just pour the fluid from the bottle, no pump needed.

 

Is anyone here familiar with the OBDLink MX+? It's not exactly clear what A/T Temp 1 and A/T Temp 2 are, but I think I should be able to figure it out by driving it around with it on and monitoring.

 

Lol

 

I have the ODB MX+ and used it when I swapped out my radiator, which required me to do a transmission fluid check. The reader works great with my google pixel phone using the ODB Link app, and finding the trans temp was easy. I can't remember which of the two it was, but is was the only one showing a temp. Using the app, I created a dashboard that included Trans Temp 1, Trans Temp 2 and Coolant Temp. It worked great.

 

@Cowboy59 -- awesome, thank you sir. That's pretty much how I have mine set up -- so am I correct in thinking that Temp 1 is the pan and Temp 2 is the converter?

 

I think that is correct, but it will be real obvious as you let your engine idle while the temps come up and just rev the engine a little and drive around the block if need be to get the transmission temp up. If I recall correctly, only one of them showed a temp. But it has been a long time.