G
Guest
I am having one heck of a time getting a straight answer from any of several Ford Service Departments.
I have a 1998 Expedition 5.4l E4OD transmission. It came with 16" rims and 255/70-16 tires.
It's now time for a tire change and I always hated how those little rims looked in the wheel well, so I'm going with some 18" rims and 285/60-18 tires.
This will increase my wheel diameter from 30.07 to 31.46. By way of comparison, the 17" rium option would have given me 265/70-17 tires and a wheel height of 31.6, so I will be VERY close to that.
As a result, my speedometer/odometer will be off by ~4.5%. I know this is not much, but I'd prefer it be right on.
I believe in 1999, Ford went with an electronic speedometer and all that is required is a reprogram of the chip to account for tire size. I've HEARD that with the 97s and 98s, it's a matter of a VSS gear change.
Yesterday a dealer tried to reprogram my chip but could find no menu option so he THINKS it's a gear change. (He should KNOW, but don't get me started).
Now supposedly the VSS gear is located on the top of the rear axle/transfer case area and held on with one bolt. I found this assembly, but instead of finding a gear unit when I pulled it, the wire was attached to a small metallic cylindrical device that I take to be an electronic sensor, but I could be wrong.
At any rate, can someone please tell me what I need to do to get my speedometer recalibrated? One dealer even told me this was illegal which is BS.
Thanks in advance, and I hope I've posted this in the correct forum.
Buzz
I have a 1998 Expedition 5.4l E4OD transmission. It came with 16" rims and 255/70-16 tires.
It's now time for a tire change and I always hated how those little rims looked in the wheel well, so I'm going with some 18" rims and 285/60-18 tires.
This will increase my wheel diameter from 30.07 to 31.46. By way of comparison, the 17" rium option would have given me 265/70-17 tires and a wheel height of 31.6, so I will be VERY close to that.
As a result, my speedometer/odometer will be off by ~4.5%. I know this is not much, but I'd prefer it be right on.
I believe in 1999, Ford went with an electronic speedometer and all that is required is a reprogram of the chip to account for tire size. I've HEARD that with the 97s and 98s, it's a matter of a VSS gear change.
Yesterday a dealer tried to reprogram my chip but could find no menu option so he THINKS it's a gear change. (He should KNOW, but don't get me started).
Now supposedly the VSS gear is located on the top of the rear axle/transfer case area and held on with one bolt. I found this assembly, but instead of finding a gear unit when I pulled it, the wire was attached to a small metallic cylindrical device that I take to be an electronic sensor, but I could be wrong.
At any rate, can someone please tell me what I need to do to get my speedometer recalibrated? One dealer even told me this was illegal which is BS.
Thanks in advance, and I hope I've posted this in the correct forum.
Buzz
