2010 Toyota tacoma shudder

I have a 4x4 2010 tacoma that has a shudder at low speeds right before the tranny changes gears. I can feel it briefly at around 20 mph and 30 mph if i drive slowly. If i drive normally and get up to speed quickly i dont feel the shudder. I just replaced the carrier bearing last year and all 3 u joints this past week. I also replaced the rear axle bearing on the passenger side. I pull a boat a lot so im hoping to figure this out asap. Thanks

 

could be torque convertor lock up

 

Could be low on ATF Fluid due to heat? Try adding some DR.AntiShudder Fix,4 oz tube to tranny and if still to low,add more ATF Fluid of recomended Type !