Ford Repair: Ford Windstar vibration shimmy, 2003 ford windstar, ford windstar lx

Question
My 2003 Ford Windstar LX van has 90000 miles on it. It has a 3.8 l engine. For the past two weeks, it started shuddering and shaking at low speeds till 45-50 mph. The steering wheel also vibrated along with the van. Now this happens till 65-75 kts. The speed is not fixed. The vibration is felt most severely at low speeds of 15-20 mph on the steering wheel. At high speeds, this shuddering of steering wheel reduces significantly.

The tires need replacement. One of the tires was not good and I had replaced it with a similar used tire. I am not sure if the shaking and vibration is only because of alignment/balancing/ worn out tires or there is another problem? Very Happy Very Happy

Answer
Anant, you must have good well balanced matching tires first. You must have this before you can consider anything else. Make sure the rims are not bent. Get NEW unused tires. You don't have to spend a fortune but do not use used tires. Have them mounted and balanced correctly (usually included for free). ALWAYS replace tires in pairs not one at a time.