Comprehensive Transmission fluid change without cooler?

So as we all know, the 2019's and 2020's don't have the transmission fluid cooler, but they do have the warmer. I want to flush the transmission fluid completely, which is easily done by tapping into the cooler return line and draining old fluid while adding new fluid and cycling through the gears. However, my 2019 doesn't have this option. And I can't find anyone flushing the system with this setup. Can I use the heating loop like the cooling loop? Would that work the same way? If so, does anyone know which line on the pump is the return? Any guidance would be helpful. Thanks.

I've got this truck in the middle of Alaska, 250 miles from a road, in McGrath. I need to do all this stuff myself.

 

Brad, I don’t know if this helps, but today I did a transmission drain and fill using the drain plug and the fill plugs only. I put a mixing bucket, which has measurements on it. Drained, and got 4.25 quarts out of it. I did it with truck cold. Manual says trans has like 8 quart capacity (rough estimate). So I put same amount back in. Messy and pain in the ass with a little hand pump. Seems to be fine with a roughly half capacity fluid change. The next time im gonna get a $20 sprayer from ace to put the new fluid in. It would’ve been worth it.

 

well worth it.

 

bprose,
Thanks for the response. Here's the thing, I had to rebuild my engine after the truck rolled into an over-flowing river. I'm afraid I got water and silt into the transmission and possibly torque converter. Which is why I want to flush all nearly 14 quarts of transmission fluid. Im thinking of disconnecting each hose to coming out of the pan, turning on the engine, and seeing which one is the return. Then treating it like I would the cooling loop. Theory and videos seem to indicate I can flush all fluid in the system, including the torque converter, this way. I'll take photos. Still open to advice, though.

 

Those hoses have coolant - not ATF.

 

So the Transmission heating system works by taking coolant to the tranny, not ATF to the engine block?

 

Yes, the two lines you see there are coolant lines and the puck shaped thing is a heat exchanger to warm/cool ATF relative to coolant temp.

 

Ok. Verified. Which brings me back to my original question, How do I flush the entire system, including the torque converter, without any supply/return loop outside the transmission? Correct me here if I'm wrong, but all ATF fluid is contained within the tranny.
I might be left with simply draining and filling the pan, running the engine while cycling through Drive/Neutral/Reverse, for 15-20 seconds, then draining and filling the pan again. Repeating this process until the ATF fluid draining out of the pan looks consistently new.

 

I was looking for which one of these to buy. I just ordered one. It takes a month to arrive to McGrath, AK. But it's on the way. Thanks for the heads-up.

 

I’ve only seen methods to DIY flush using the trans cooler, which you don’t have based on your picture. I’d try multiple fill and drain cycles with less expensive WS compatible fluid (maybe three) then two with your WS ATF of choice. I’d do more than warm it up, maybe drive it a week between. It’s probably overkill but learning transmissions seem to like gradual fluid changes.

 

On my 200 Land Cruiser (same engine), I just use a funnel with long clear tubing (mine is around 4.5 ft.) and snake it through the engine compartment to the fill hole on the transmission. A 5/8 hose will jam in tight in the fill hole and not move. Simple, clean and easy. Just avoid the exhaust as you route the tubing.