First of all I want to say thanks in advance for any help.

My truck (automatic tranny) is shaking under light acceleration mainly between 45-60 mph but also happening above 70mph and occassionally as low as 35mph. If I jam the gas it goes away. Aside from that, I've been managing with this issue by turning off the overdrive, which aside from providing terrible fuel mileage, solves the problem on the highway for the most part. However, with overdrive off, the shuddering starts to occur more frequently at lower speeds (25-40 mph). So I am switching it on and off constantly.

From what I have read I am thinking this is a torque converter or transmission problem. Any ideas?

 

1. Check for codes, 2.Try a tune up ....plugs, etc....produces the same symptoms