Speedometer gear/TSS

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I have a 99 Explorer Sport that I purchased new in Jan. of 99. It's just a base model 2WD 5-speed manual (M5OD-R1). I recently put 31x10.5 tires on the stock rims and swapped out the stock 3.27 gears and open diff with 4.10's and an LSD I purchased on eBay.

My question has to do with the speedometer. Obviously with the different tires and gears it is no longer accurate. Not off by too much (reads about 5mph slower than actual at highway speed), but I wanted to recalibrate it anyway. I thought that I would just be able to change the speedometer gear, but then I read a few places that like 98 and up are computer controlled and you have to go to a dealership and have them recalibrate it. I have spent all day researching this and still can't find the answer. I need some help if anyone knows for sure?

Also, if I can just change the gear, where is it located? There are no sensors or electrical connections on the tailhousing of the transmission. I do see one at the top near the middle of the unit. There is also one on top of the diff, but from what I gather, this is the ABS sensor.

Can anyone help me? Thanks in advance.

 

[albi1cnobi1]

On your 99 there is no speedo gear. What you've heard is correct, the ABS control unit gets it's speed info from the VSS in the rear diff. The ABS unit then sends the signal on to the various systems that need it.(speedometer, PCM, etc.) You can either have a ford dealer re-calibrate the computer, or get an after market unit and do it yourself. Dakota Digital makes one, and I believe Superlift makes one called the Tru-speed. You can also do this with a tuner such as an SCT or similar iirc. I've never gone the tuner route, but thats what I've read.