2003 ranger 2 wheel drive 3.0 engine with 235,000 miles . had antifreeze leak and took it to autoshop . timing chain cover was leaking .they replaced gasket,new waterpump,changed oil and put 2 new stabilizer bars because one was broke.when I got it back and drove it everything was ok till I hit passing gear and the engine shakes really bad.took it back and they checked it out and couldn't find anything.so they put a new harmonic balancer on but that didn't help.they checked u-joints,trans and sensors but still the same ,so they gave up.all iknow is there was nothing wrong before this work was done.it drives ok if I take it easy .I can go to 70 with no problem,but at any speed low or high if I kick gas pedal down hard it shakes.could they have done something wrong with the work they done . any ideas would helpful please. ..

Check the u-joints and check drive shaft for dings or damage.

They could've damaged the crank sensor, or if they had to unhook the fuel lines, they may have got dirt in the lines.

they noticed fan wobbling so they took fan and fan clutch off put belt back on and drove it and there was no vibration so they put a new fan and fan clutch on and drove it and vibration came back . so they put a new water pump on and no vibration .so problem solved . they said the pump was bad . it was a new car quest pump they put on when they replaced the gasket