Tranmission Issue

My 2009 DCSB got 159k miles on it and when i am driving it for a while on city streets, when i take off, then at mile point around 30, 40 , 50 , it shakes like its having problem shifting into next gear.
Took to Taco Dealer said , needs new transmission. took to honest guy, said it is not trannny issue. took to another one, not a transmission issue. balancing and alignment ok, just did a month ago. Help!!

 

You might try this to see if it is torque converter shutter.

To quote Gearcruncher

https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

Here is how you can test for a converter shudder from home .

Allow the truck to warm to operating temp . Your converter will not lock up when its cold .
Place the shifter into the overdriveposition and drive until you feel theconverter shudder .
Once you begin feeling the shudder , use the " Brake Tap Test " to see if the shuddering goes away .

As soon as you feel the shudder , use your left foot and gently tap the brake pedal about 1/4 inch down but leave your right foot steady on the gas pedal .
The idea here is not actually hitting the brakes but manipulating the brake switch . Manipulating the brake switch tells the computer that you are coming to a stop . Your computer will then command the converter clutch to the off position for a couple of seconds . When the converter turns off , your shudder is going to go away for a brief moment .
Because , you only tapped the brake pedal to manipulate the brake switch and you still have your right foot steady on the gas pedal , the computer in your truck will then command the torque converter to re-apply the locking clutch and your shudder will instantly return .