Trans drain and refill - level question

Hello,

Looking for advice / opinions / recommendations.

My 2016 Limited 4Runner has come to 100,000 kilometers (about 60k miles). Even since new I noticed a very slight grease / oil film on the transmission lines, not enough to warrant the local dealer taking apart my trans. Truck runs fine, no issues, I don't tow or offroad either.

I am about to do a drain and refill on the transmission fluid. My research points to measure what drains out, add half quart, refill then follow the temperature opening the check plug / overflow bolt procedure.

My concern is this, if the trans fluid has indeed been leaking it would be lower than it should, how would I know I have topped it off enough without the temp getting passed the sweet spot of 100F (I am assuming its only a few minutes window). To add to that, if the fluid is at 100F and I add more, would that not give me a false reading as the fluid added later is at ambient temp?

One of the ways I was thinking to solve this was when it comes to refill time, I keep filling until it comes out the check plug / overflow, get it to temp, then drain. Would this approach risk damaging something?

Or am I overthinking it?

I need a lot of years from this truck that's why I am doing all this myself so I know everything has been done perfect, even down to bolt torques with the TLC it deserves. Had a bad experience when it was under warranty and the oil filter was overtightened.

Anyone in the Brampton / Mississauga / Caledon (Canada) area that would be willing to give me a hand with my first trans drain and refill?

Also, thanks for keeping this group running, its been great source for information!

Thanks in advance.

 

You are overthinking it. Add an extra 3/4 of a quart then. Or put some more in and try again. It's not how much you put in that's critical. It's how much you drain out through the overflow.

 

What is interesting is the care car nut guy says many times in his videos, 'if you are going to do a job, do it right." Replacing all the fluid is doing it right. Unplug the transmission line from the cooler and flush the old fluid out and refill two quarts at a time until you flush out the old fluid. 12 quarts. it is easy. Just do it.

 

When I did my transmission fluid I was low when I did the fluid check. I actually had to do the check a couple times adding fluid in between each time. I suppose it's possible for the different temp fluids to make things off by a little but I doubt by much.

The temp seemed to hold pretty well between each time I did the check (shutting the engine off each time I added fluid).

I wouldn't sweat it too much. As long as the temp is reading in range and fluid comes out it'll be fine.

Edit: When I did the fluid exchange it pumped out 2qts in 30 seconds. So the fluid is moving and combining pretty quickly.

 

Car Care Nut also says drain and fill is good but don't over do it.
https://www.youtube.com/watch?v=jJr30r6RRgw
Great video.

 

I do the simple drain and fill. The check bolt makes life super easy. Drain out when warm. Measure quantity, input NEW quantity drained out, and add some more until it runs out of the check bolt hole. It's hard to mess up.

 

Having a scan tool capable giving "live data" tranny temps is a big help. There is a method of jumping terminals in the OBD connector. Although not a fan of that method. Yes your overthinking it. https://www.4runners.com/threads/monitor-trans-temps-torque-pro-app-android-obd-jumper-method.25302/

 

Dont want to get involved with complete flush, Car Care Nut and Scotty Kilmer both seem to be against that after a certain mileage.

I was going to go with the approach of a drain and refill every 60,000 Kilometers (approx 35000 miles).

For those using the OBD Fusion to get temp, which A/T Fluid temp is for the transmission fluid? I have two come up on mine, they just show as "A/T Oil Temp" 1 & 2.

Thanks,

 

A/T Oil Temp 1 is the valve body temp and A/T Oil Temp 2 is the torque converter temp. If your 4 Runner is just idling waiting to get the temp up, they will run almost identical numbers. But A/T Oil Temp 1 is the one you want.

 

Hello Team, just wanted to give you all a heads up. I did the trans drain and refill service (thank you again to this group). When I drained the fluid I got about 3.5 quarts out, when I went to refill it used nearly 5 quarts (I followed the wait until 100F to pull the check bolt, first time around no fluid came out at all had to add a quart and half extra).

I'm thinking that leak I mentioned did in fact lose nearly a quart over 100,000 km (approx 60,000 miles).

One of the ways I found the leak was when doing an oil change there are two beams which the first (front front of truck) skid plate bolts too, one of those beams had no rust at all and was oily which I traced back to one of the trans lines leaking. A friend of mine says he saw the same oil on one beam thing on his FJ.

Its still not enough for me to want anyone to try and repair it, but I do think I will be doing the trans drain and refill every third oil change.

Anyway, wanted to give everyone a heads up to avoid any damage to your 4Runners.