Rough Shift / Slams into 4th Gear

I have a 2011 TRD Sport 4wd Automatic with 105K. Lately I've noticed rough shift between 40-50 mph, usually after letting off gas, then easing back on the pedal to accelerate. Sometimes it feels like a shudder - like it's searching for the gear - and then it will slam into 4th. It will never do this when driving with shifter in 4th, only does it in D. Usually occurs on level roads, not under load or uphill. Happens without cruise control. I brought it to Toyota dealer, they reset the ECU? and said it has to re-learn its shift points.
I left the dealership, went for a drive, and it still has the same problem. I brought it back. They are trying to figure it out. Could it be torque converter?
Not sure if second issue is related, but every now and then I get a rough idle with foot on brake in gear at stop light - it will "cough" for a few seconds then clear up. Never occurs in neutral or park, or in motion.
Any ideas???

 

Could be the torque converter. When did you change the trans fluid?

 

Full drain and refill of the trans cures like 90% of the problems people have with these trans.

 

Are you sure its 4th gear and not 5th ?
Clean the throttle body and mass air flow sensor to start . If that doesnt fix the issue , follow what Nd4speedbh is recommending by changing all the fluid .Your first fluid change was due at 60k , Was the transmission service performed ?
Got some info here that might help
http://www.tacomaworld.com/forum/te...hift-kit-shift-recalibration-kit-2nd-gen.html

 

Dealership #1 did a diagnostic while I drove, sent the engine data to Toyota Corp and they recommended a transmission flush 3 times. Still had rough shift and rough idle after that.

Dealership #2 did a diagnostic while I drove the vehicle. Tech noticed engine misfire before we left the parking lot, while foot on brake in gear. It was cylinder misfire on the diagnostic. I had a cracked spark plug that was installed 10K ago. Cylinder misfire was causing rough idle at a stop and rough shift from 5th to 4th. New spark plug installed -- problem solved. It was covered under warranty since it was a Toyota plug installed at dealership. No charge.

Dealership # 1 - refunded service charge since it had nothing to do with the actual problem.

 

It's rare that I have anything good to say about dealership service depts., but in this case you got lucky.

#1 - misdiagnosis - but service $$$ refunded
#2 - found actual problem and fixed.

We should all be so lucky.

Glad your problem was resolved.

 

Yeah stars aligned for the OP for sure.