After driving through some very deep water I changed out Front & Rear Diffs and Transfer Case fluids. Found water in Front and Rear Diffs but not in the Transfer Case. The front diff breather sits high in the engine bay close to the same height as the intake, I got lucky.

Anyway I checked oil and it was fine but didn't think about the transmission until I saw this video. https://www.youtube.com/watch?v=FcYoGg5V_VE

This guy goes through some water that was about as deep as what I had driven through. He was not so lucky, he posted in the comments that 1 month later he had to replace his transmission and had water damage.

SO...I decided I would flush the transmission today

I couldn't find a dedicated DIY for our 5th gens...I used this DIY as a template, although its a 2wd tacama it was similar with the 750 transmission - > I'll note the differences so others don't have to piece together a bunch of threads. If I get some time I'll put a dedicated DIY here but for now this will do and hopefully save you some time.

DIY: Full Automatic Transmission Flush - Toyota Nation Forum : Toyota Car and Truck Forums


Difference #1: Fluid Temp Check, use the D light instead of an AT light described in these other DIY's
1.) Jump pins 4 and 13 on the OBD II plug
2.) Start your truck, and watch the dash lights flash
3.) Shift to Neutral for 2 seconds
4.) For 6 seconds (approx 6-8 shifts) go back and forth Drive, to Neutral with a very short pause
5.) During #4, watch your gear indicator on the dash (D, N, D, N, D, N) when you shift back into N after the 6 seconds are up the light will switch to D for 2 seconds and go back off
6.) If the D light doesn't come on while in Neutral after 6 seconds of shifting shut off the truck and start back at #2, it can take a couple tries
7.) Put the truck back in Park, the indicator will be blank
8.) Pull the wire from the OBDII plug, let truck warm up for about 15m
9.) When hot enough, the D light will come back on solid, indicating you are at the proper temp to check the fluid level
10.) If the D light is flashing, your truck is too hot, let it sit for a while and come back later

Difference #2: Return Line disconnect location
You will notice the return line from the Radiator in this guys pictures and description is separated on the passenger side and fluid then comes from the steal line...

In the 5th Gen, your return is on the driver side of the radiator, disconnect is easiest from the driver side where a short hose attaches to the steal line at the bottom driver side of radiator. Fluid will flow out of the hose, grab a 3/4" ID hose and just slide it over the top of this hose to transfer fluid to a bucket

I used that link that you referenced as well for my 2009 4runner. Worked like a charm only difference was the sequence how to put the transmission in temp check mode was different.

It could be possible that the steel lines were slightly different based on having KDSS on my 4runner

Did you find any water in your tranny fluid?

No sign of water, I have 21k miles and the fluid was already a dark brown/red but no burn to it. I’m glad I flushed it out for peace of mind but I’m sure it would have been fine.

The breather for the transmission is on the same bracket with the breather for the transfer case and front diff, above the driver's side wheel well.

The trans fluid will turn dark brown after a few miles of use; looks the same after 100k miles.

I always forget #2 and end up making a huge mess in my garage. On the plus side, the trans fluid does a fantastic job of cleaning everything.

4RLaw/Others -- anyone have a picture of where to disconnect the hose for the drain/refill spot? It's different from my 4thGen (which was super easy). I want to make sure I'm in the right place! Thanks!

Anyone?

I'm tackling this on Saturday so would appreciate any intel!

Got it done today, pretty simple and straight forward. Drained, replaced filter and flushed a total of 13 qts. The place to tap into the line is under the front of the motor, on the right side. Remove the front steel skid plate, trace the top steel (return) line from the transmission, separate the rubber hose from the steel hose, hook your bottle and pump to the steel return line, and hook your drain line to the rubber hose.

I'm ready to do this job. You mention to tap the line under front of motor on right side. Is that drivers side as stated a couple posts back or passenger side as I imagine when I think 'right'? Did you happen to take a photo?

ALL FLUIDS GUIDE: Beginner Fluid Maintenance

I bought the "Scangauge2" and used these codes: ScanGauge II Has anyone used one for the 5th gen? | Toyota 4Runner Forum [4Runners.com]

Worked perfectly. Just a suggestion.