hi ,

i have my 1994 chevrolet silverado 5.7 4x4 , 4l60 e trans. i had the trans rebuilt with a new torque convertor . as i was driving when it first thing from start to 50 miles per hour everything is fine but as soon as i come to a incline or hill and go to speed up it feels like i am running over rumble strips as the steering wheel and the dash and trucks shakes as if i am driving over them if i let of the pedel just a little or tap the brake it will stop or if i spped back up it will do it again . it does not do it all the time and seems to rarley do it once i drive for a about 50 miles or so . they thought maybe it is a torque convertor shudder but i took out the trans and installed a another new convertor and it seems to be worse . but i will only do it between 50- 65 and i have speed up to 70 miles to hour and it has done it . just like you are driving over rumble strips really fast as the steering wheel and dash shakes pretty hard . could it be the engine or the new torque could be bad . thanks also no engine light on .

Could be tires out of balanced or driveshaft bearing bad/loosed. Have those check as they are the cheapest route, and they effect the driveline vibration. I don't think after replacement of the converter that its bad too...seems line a driveline problem from your description.