31 inch tires on a 97 Pathfinder???

[mr_billcollecta]

I put a set of 31 in Dunlap tires on my 97 pathy. My ride shakes at highway speeds (60 mph and up). My brother suggested that i get a preformance chip to adjust the computer so that the car can function like the it was ment to be driven on 31 inch tires. Is there any thruth to this? Or is it my choice in tires?:help

[Grant@tirerack]

31" is a fairly large O.D. size for this vehicle. If it happens at a specific speed I would look at road force or balance issues. If you can feel it more in the seat, look at the rear tires, if you get more of a shake in the steering wheel, look at the front tires. I would hook up with a shop that has the Hunter Road Force balance machines. That will likely narrow down the vibration. You can also try to rotate front to back and see if the vibration moves.

[mr_billcollecta]

Thanks Grant. You dont know how much I appreciate that info. Im getting ready to give it to my wife so she can haul the kids around in.