2011 Tacoma 4 speed Auto Transmission shudders when changing gears

This truck has about 115,000 miles on it. The torque converter was replaced by the dealer about 40,000 miles ago.

Whenever it gears up into 2nd or 3rd and normal to slow speeds (I have a pretty light foot) I get a shudder for 2-3 seconds. I haven't really noticed it going into 4th. If I accelerate aggressively, I don't feel it.

When I first get in the truck in the morning, I don't feel the shudder for the first 3 to 4 miles, and that usually involves 3 to 4 trips through the gears.

I was going to check the ATF fluid, but imagine my surprise...

Any help would be appreciated.

Kevin Banes
Agreed. First check the fluid level. There is a very specific procedure. Follow the procedure to the letter. Its not difficult, just need to execute accurately. The procedure can be found on the Internet.

Typically, the Gen2 AT needs the fluid changed at 30 kmile intervals. Your fluid is about 2-3 intervals behind.

Frankly, I'd do a fluid/filter change, then see how things behave. Don't bother with a flush. A flush is expensive and is known to cause other issues. Changing fluid/filter is not a difficult task. Simple ratchets and sockets are the only tools needed. Parts are simple, fluid, filter, gasket. A fluid pump can be handy and you would need a jumper wire to initiate the fluid level check procedure.
Yep, dow a fluid change first. Some, I don't know about Toyotas, have a plug, some don't so you drain by loosening the pan. Regardless get a large catch pan. Many plugs are magnetic so check and see if there are any bits of metal, no mater how small, stuck to the plug. No plug it usually settles out in the pan. Autopsy the filter as well. If you have any metal that's bad news, contact a tranny shop. No metal just wipe the pan well and put everything back together. Make sure you follow the level check procedure for your model. You don't want to overfill, causes foaming and then it won't work properly.
OK, more to my story.
I am too old to crawl around underneath this thing to change the fluid. and it just seems too complicated. So, I took it to the Toyota dealer.

They had for about an hour. The service advisor comes back and tells me that they want to test the hydraulic fluid for engine coolant contamination. I give the OK.
He comes back in about 30 minutes and tells me that yes, the transmission needs to be replaced due to engine coolant intrusion. The cost will be $4500, and it will take about 30 days to get one in.
I ask the guy "where did the coolant come from?", wondering why we arent talking about fixing the ATF cooler in the radiator that is allowing the leakage. He gets up to go get the service manager, since he is not equiped for this conversation.
The service manager starts off with the question about the torque converter that this dealer had replaced about 2 years ago. I interrupt, and ask about the coolant leak. The service advisor tells me that there is no coolant leak. He made a mistake about that part. So, the service manager says that since they replaced the torque converter about 2 years ago, they now need to replace the transmission. I'm a little confused about how we got to replacing the transmission so fast. He tells me that (paraphrased) the bands and stuff get just get worn out, and its just time. I ask him how, if it is a mechanical failure of parts, why is it that the transmission works fine for the first 10 miles/10 minutes in the morning? He tells me that it is because the problem is not apparent until the fluid heats up.
I tell him that prior to charging me $4500 for a new transmission that he can't get for 30 days, why don't we just change out the ATF fluid? He told me that we could do that, but the transmission is bad. I ask about changing the fluid anyway, and I am told that it cost $303, and he starts to explain how complicated it is, but it doesn't matter, because the transmission is bad. So, again, I ask him if I am going to replace the transmission solely on the fact that I get shimmy during upshifts, and the fact that they replaced the torque converter 2 years ago. He says yes.
At this point, the service associate also tells me that I need to replace the front brakes, as I only have about 2 mm left on the front pads. I explained to him that I put new pads on the front brakes 10 days ago. He can't figure how that can be.

So I left. I am going to find someone else to change the fluid out.

From the paperwork, this is what the technician said:

"Tested fluid for gylcol intrusion twice. Both test passed, meaning no coolant is entering the transmission front the cooler that is built into radiator. Tech recommends replacing the transmission due to torque converter shudder and intensive shift operations. Transmission is about a month out."

Does this sound like a problem with a torque converter or with the transmission? Why would they be begging me to change out the fluid? What is Torque converter shudder?

Is Aamco a reputable transmission shop these days? I live in Baton Rouge, La., but I don't see a lot of transmission places that have a bunch of positive ratings.

Any comments/suggestions would be appreciated.
If you have an ACE transmission shop, have it checked out by them. They actually rebuild them. Something doesn't sound right about this brake pad deal if you changed them 10 days ago, and the dealer is claiming they're nearly worn out already. Either the dealer isn't honest, or the pads were never changed in that time frame.
As far as the transmission...if replacing new atf doesn't help, the transmission needs to be replaced, or rebuilt. It's that simple.