Hard Shift on gear 4,5,6

I have a 2015 SR5 crewmax tundra with 110k miles on it. I haven’t had any issues with this truck. Over the past week I have noticed a hard shift between gear 4,5,6. I haven’t done anything to service the transmission yet. What would be causing this hard shift all of a sudden?
I can’t check the transmission fluid there isn’t a dip stick. Any advice would be great before I take it to the dealership and they give me the run around.

 

I think you answered your own question. I would do a fluid flush and fill at a minimum and see how it goes.

 

So start with a fluid flush and see if that fixes it? Filter to or only flush the fluid? When I talked to Toyota they said that transmission is good for the life of the vehicle I’ve never heard that.

 

Most people agree that's a gimmick. I would do just the drain and fill and see what happens. You can even repeat it after few thousand miles if theres an improvement. Filter is not usually needed but if all else fails you can try as a last resort.

 

https://www.tundras.com/threads/15k-miles-transmission-drain-and-fill.88277/

https://www.tundras.com/search/4089650/?q=Transmission+fluid+change&t=post&o=date&c[title_only]=1

 

Just be careful with the word flush when taking it to a service shop. Also think about cleaning your MAF and throttlebody. That’s maintenance that should be done even if it doesn’t fix the problem. But a dirty MAF can cause some hard shifts. In my experience it was all the gears not just 4,5,6.

 

Awesome I will look at this as well. Sorry I’m not very mechanically inclined what are you referring to MAF?

 

https://youtu.be/DDgbiHe__j4
Mass airflow sensor. It is located on your intake tube, you’ll see a couple‘s wires connected to it. Just get yourself a can of MAF cleaner, disconnect the wires leading to the intake tube, two Phillips head screws and pull it out. Don’t touch the sensor portion of it physically, just spray it off with the cleaner. You can also take this time to clean your intake tube if it’s dirty. As well as inspecting your throttlebody and cleaning that as well. I’m sure there’s a good YouTube on that one too.

 

Awesome man thanks for the advice going to give that a shot this weekend

 

Hard shifts are one of the first signs of trans fluid changing its composition with age. The friction modifier goes and changes how the clutches slip in the shift. I've seen just heavy towing do this in well under 30k miles with the WS. The truck shifted very hard especially in 4-6 when the locked torque converter stopped insulating shock from the engine. Twice it's happened, and both times a full change of fluid made it run like new again. That truck stopped towing duty about 3 years ago and like magic the fluid hasn't broken down again.

The old Honda ATF Z1 was awful for this. I did a drain/fill of the transmission fluid every year or so to refresh the additives otherwise it would start slamming gears. Enough Honda autos failed back then to convince them to reformulate the fluid but just a little preventative maintenance kept it going on the original sauce for hundreds of thousands of miles with no teardown.

Which reminds me, mine's due for a pan drain/refill this year. It works out to about 1/3 of the total fluid.