2012 Toyota Tundra - Transmission Issue

Hi! I am a new sign up, but have been searching these forums for a while when I have truck questions. However, the issue I currently have is a bit unique, but yet similar to what others have experienced. I'll get right to it.

Specs: 2012 TOYOTA TUNDRA / 2WD / 5.7 ENGINE

Issues: On cold starts, the vehicle goes into reverse without issue, no revving needed, however, once the motor, or transmission warms up, there is no power in reverse, or sometimes requires a hard rev to do so.
Sometimes, if in reverse, I hard rev the engine to about 3-4000 rpm, the truck goes reverse for a moment, and I have to keep hard revving to go into reverse normally, without need to press accelerator.
Sometimes, after 1 or 2 hard revs, it will go into reverse and operate normally. Oddly, after driving for an extended amount of time, possibly for over an hour, it will go into reverse just fine.
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While driving, 1st to 2nd gear is smooth, with holding on 2nd longer than usual, then shifting to 3rd. From 3rd to 4th, there is a slight dip, like a downshift almost, before shifting into 4th. When cold, it will stay in 4th. When motor/transmission warms up, it will then shift to 5th and 6th gears. When shifting, there is no hard sounds, but otherwise a smooth shift. It is similar to driving a manual, and holding the gear to long before shifting. After driving, shifts become smoother, albeit for 2nd to 3rd may still lag a bit, but not as much as cold starts.

Notes: All gears operate fine. The truck does not go forward in neutral or reverse, as some have reported. I am able to push the vehicle backward or forward while in neutral as well. Once driving on the road for some time, the vehicle shifts to 5th and 6th gears as normal, smoothly driving at speeds over 100mph (for testing purposes) with no slippage or sudden downshift.

Codes: P2714 - PRESSURE CONTROL SOLENOID "D" PERFORMANCE/STUCK (main code read)
P0761 - SHIFT SOLENOID "C" PERFORMANCE/STUCK OFF (not common)

Services Performed: Had transmission serviced, with replace transmission fluid, filter, replaced solenoid "D". Vehicle worked normally for a bit before returning to issues.

If any has experienced these specific issues before and found a solution, your assistance is greatly appreciated. While the shop recommends replacing the transmission, not for what's wrong, but the amount of time and money it would take to fully diagnose and repair the issue, I am confident the transmission only needs specific maintenance to work correctly. Honestly, I am no mechanic, but a person who is hopeful a full replace is not the only answer.

Currently, I am driving the truck back and forth to work, and some areas are almost 2 hours away. The truck otherwise drives fine despite the issues mentioned.

 

With those two codes, I would have replaced solenoid C. The pressure solenoid code is usually a head fake. Did someone test the solenoid C?

 

Thanks for responding! Checking the repair reports, I am unsure if the other solenoids were checked. However, I will have solenoid C tested based on your recommendation. Do you think it would be beneficial to replace all the solenoids?

 

I would only replce those that fail the tests.