QuestionI have a 2004 Ford Explorer XLT 4WD with 35K miles. One tire has worn significantly on the inner and outer edge and have no tread. The other 3 tires have about 40% even tread wear. I would like to replace just the front 2 tires at this time, but the dealer has told me I must replace all 4 tires or I would cause damage to the vehicle and experience tremendous shaking/vibrating at speeds over 45 mph if I do not replace all 4.
I had intended to replace the new tires with tires of the exact same size that are currently on the vehicle.
Can you tell me if the dealer is correct and if I would suffer great harm to the vehicle and my ride enjoyment if I only do 2 tires at this time? I am leaving this weekend for a long car trip and want to get some additional advice.
AnswerDiane,
Simple answer: It is good policy to have tires of the same size / make / model / state of wear on any AWD and 4X4. Since the tire dealer doesn't know which vehicles are sensitive - and which aren't - he has to rely on that simple rule. That way he is protected in case the drivetrain fails.
But the folks that know the answer to that question work at Ford. They designed the drivetrain and should inform everyone what the tolerance is for differences in tire diameter.
I am not aware that Ford has issued such guidelines, so I am left to take a wild guess.
The problem, the way I see it is "risk". It is clear that too much difference in tire diameter will cause problems for the drivetrain - which will eventually fail. But in the absence of a guideline from the manufacturer, what should you do?
The risk is the cost of tires vs the cost of repairing a drivetrain. We're talking several hundred dollars vs several thousand dollars. This risk analysis seems to point away from the replacing anything less than 4 tires.
