I just got back from taking my 2020 4R into the dealership for, among other things, a transmission fluid drain and fill. When reinstalling my RCI skid plates (I had taken them off, not just to make their job easier, but to ensure they were re-installed correctly), I noticed that the drain and check plugs appeared to not have been used/removed. There was no sign of those areas being wiped clean and am pretty sure there were no new washers on either plug. So, did my dealership actually perform a drain and fill? Do they have a another way of doing so that doesn’t use the drain and check plugs at the bottom of the transmission pan? Was the mechanic just so proficient he could do it without leaving any evidence? Or, did they possibly not do it?

Just curious….Thanks!

Other posts discuss this issue. Dealer connects a fluid exchange machine at one of the ATF cooler radiator connections. Remove the skid plate and you might be able to detect if one of the hoses was disturbed at the lower reservoir of the radiator.

Is that considered a flush? Or do they just replace all the fluid in the transmission this way?

A transmission fluid exchange machine is used to exchange all the fluid. Some shops call it a transmission fluid flush.

My point/question is if its a flush it is under pressure and fluid is forced out with a separaye pump.. Fluid exchange is fluid coming out.of transmission goes into separate tank and new fluid is pulled in.
Flushes are bad, at least in GM transmission.

Even with an exchange or flush, Good dealers will use the Toyota SST atf tool and check for the correct level at operating temp.

I would not take a vehicle to a shop that advertises a flush that includes a chemical cleaning and chemical seal reconditioning. The word flush is a descriptive word and does not necessarily imply excessive pressure during a fluid exchange service. Ask to talk with the shop foreman, ask him your questions, ask about the procedure, and establish a relationship with that shop. If you can find out what machine they use, look up the manufacturer operating manual and post a link here.

Thanks everyone. I was clear to confirm with the dealer to do a drain and fill, an not a flush. In fact, they stated that they do not recommend a flush, but just the drain and fill. Anyway, it bothered me enough that I called my service advisor this morning. He assured me that the tech did the work and that this person has never had any complaints or issues. And while he didn’t watch the work being done, he saw the vehicle up on the lift, which would have been necessary for the drain and fill, and not the other work that was performed (AC high-pressure line replaced where it rubbed against my winch and wore a hole). He basically assured me it had been completely properly so I’m going to trust at this point.

I would not let the dealer do a flush. It could ruin the tranny.
Do the proper drain and filter change.

I Told My Customer Not to do This, Now His Car is Destroyed - YouTube


If you feel that they might have cheated you (possibility) redo it yourself.

Assuring means nothing. That is why I only trust myself working on my cars..
talk is cheap....

Did you call and ask them?

A drain and fill requires drain plug and fill plug to be removed at a minimum, level plug of course needs to be removed to correctly check level.

Sounds like they didn't do anything.

Our local Hendrick Toyota dealer had it labeled a power flush, I had it done for $210 about 15,000 miles ago at 144,000 miles.

Shifts great, but at first I noticed the shift points weren’t quite where they were before the service, but now it’s back to normal.

The service manager said if I had gone past 150,000 miles, they might have declined performing the service. The transmission fluid had never been changed before that.

That's a complete flush they did which is fine and dandy. Pretty stupid not to drop the pan to change the filter and clean pan. Check magnets for wear and tear.. that's what you get from the dealer though.. half ass 👽