speedo regear?

BLUTO · Apr 7, 2004

I have a 2000XJ 4.0L, AW4, 242.....I just changed gearing from 3.55 to 4.10's. One friend tells me to change the speedo gear in the TC to a 40 tooth unit. Another friend tells me that the speedo is computer controlled and you must "flash" the chassis ECU to effect the change. Who's right?

BLUTO

Bryan C. · Apr 7, 2004

I would say friend #1 is correct depending on your tire size. Check out Go-Jeeps webpage for the correct speedo gear to buy.
http://go.jeep-xj.info/HowtoSpeedoGears.htm

Bryan

juicexj24 · Apr 7, 2004

I have 4.10's with 33" tires and the NP242. I got the speedo gear from M.I.T. Tech in Ca shipped for 17 bucks. 35 teeth. Dealer has been out for months now. Something to look into. Their number is 619-579-7727. You will need to know if it's long or short and what tooth count you need. check out the go-jeep site for help. Juice

BLUTO · Apr 8, 2004

I used GoJeep's gear calculator and came up with 41 teeth for 4.10's and 31" tires (40.4 teeth + error on the side of reading fast :guitar: )
My speedo was within 1 mph on GPS with 3.55 gears and 31" tires. Ordered 41 tooth gear tonite from dealer (-25% employee). 41 tooth gear is almost twice the cost of 40 tooth gear :dunno: :scottm:

BLUTO

1986xj · Apr 8, 2004

Anyone happen to know if there are still gears available for the 207? And I wonder if the tooth count #'s from gojeeps site would apply to it? Looks like I would need a 38 if it does. I'll ask at the DS parts counter tommorow but most of the time I just waste 1/2 an hr there and walk away empty handed since they rarely have anything I want in stock.
Mike B.

Wayne Sihler · Apr 8, 2004

BLUTO said:
I used GoJeep's gear calculator and came up with 41 teeth for 4.10's and 31" tires (40.4 teeth + error on the side of reading fast :guitar: )
My speedo was within 1 mph on GPS with 3.55 gears and 31" tires. Ordered 41 tooth gear tonite from dealer (-25% employee). 41 tooth gear is almost twice the cost of 40 tooth gear :dunno: :scottm:

BLUTO

I am running the same combo,4.10/31s and "calculated"the spedo gear to be 39 teeth.This turned out to be WRONG.Actual mph was reading 5 mph faster(@55) than speedo was showing.
Ordered the 37 tooth gear yesterday,They do not make a 38 tooth gear for the short style gear.
HTH
Wayne

speedo regear?

BLUTO

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Bryan C.

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juicexj24

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BLUTO

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1986xj

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Wayne Sihler

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