1989 Toyota pickup vibrates when accelerating

Could be a few things..tune up needed, motor mount broken...you didn't give enough info. Does it shake if you give it gas while in park?

has a recent tune up, vibrates when accelerating over 40 MPH, usually 4th or 5th gear. started suddenly two weeks ago when traveling on freeway at 55 MPH. revs in neutral and no shaking or vibration. let up on gass and smooths out immediately, but step on throttle and vibration immediately returns. Can it be carrier bearing? or something like that?

Is vibration in the steering whee, the entiren carl or the seat? It sounds like your tires need balancing/rotating.

Vibration feels like the entire truck vibrates, you can hear the vibration and feel it in wheel and seats. the driver outside mirror vibrates enough the image is not clear, but the Passenger side outside mirror is not vibrating. Only vibrates when throttle pressed, coasts without vibration. most vibration occurs under power in 4th and 5th gear, flat road uphill or down hill vibration is the same.

Did you ever figure out the problem? My truck does the same thing

Mine as well, once I’m about second gear, super rare one day it started and don’t know what is wrong