Shake n Shudder

Last month I picked up a 2014 DCSB Sport with 64k on it, the a/c compressor started squealing like a pig the second week (and hottest week so far here in WA), just glad I bought a warranty with it so I only paid 100 bucks to get the compressor replaced. But, there is a shudder and shake when I have the gear selector in "D" at 40mph. I always switch to "4" when I hit town and the shakes will immediately go away. Sounds to me an RPM issue, but I'm new to Toyota but know how bulletproof the trucks are, been driving a 99 Cummins forever (294,000K) and do ALL of my own work on it. Any thoughts are very much appreciated.

 

Sounds almost like Torque Converter shudder.
Go here and read about it.
https://www.tacomaworld.com/threads/transmission-5-speed-automatic-write-up-with-pics-for-second-gen-4-liter-trucks.289913

Towards the bottom you will see
“DIAGNOSING converter clutch shuddering from home .( BRAKE TAP TEST )”
Do this and see what happens.


Then you can read this, as it sounds just like your issue.
https://www.tacomaworld.com/threads/a750f-shudder-issues.529098/