Topic: A question about speedometer gears

[bigbrad_4x4]

First of all, I've read the article on speedometer/odometer calibration.  I wasn't sure what tooth count I had, so I used the chart, which said to use a 41 count gear with a 28" tire, so I based my calculation on that and bought a 37 count for a 31" tire.  I swapped them out and found I had a 39 count.  I recalculated and came up with a 35 count.  So my question is would the 35 be more accurate for highway speeds (up to 70 mph)?

Thanks,
Brad.

[Jeffy]

I think the 35's going to be way off.  You're only moving up less then 3" so it should be a few teeth.  Typically it will take two tries to get it right on, if you happened to be anal about having the correct speed.  It's best to double check the speed with a GPS.  After you've done it a few times, you'll be able to get closer if not perfect on the first try.  Luckily the gears are only $12.

[jcsanders79]

Speaking of spedo gears, I have ordered an extreme short shaft SYE from PORC (hell of a deal @ $260 and no shipping).  Its 3" shorter than a standard SYE and 1" shorter than an Atlas.  This kit eliminates the speedo gear and I am supposed to visit an OEM dealer to get the ring tone calibrated.  Any one done this and know how much it will cost me?

[aw12345]

it should not be that involved but you need a chryser DRB2 scantool to change the amount of pulses per mile. say the tone wheel has 13 teeth then they just change the amount of pulses per mile to make it accurate.

Art

[jcsanders79]

I got a little worried when I called my local Jeep dealer and they had no clue what an SYE was or a ring tone spedometer.  Maybe I should try the one a little farther from town?