LIRX

I am going to be doing ther kia ring and pinion swap (4.77) so I am wondering who makes a speedo gear to recalibrate the speedo? Mazdatrix doesn't which suprizes me.

trochoid

iTrader: (6)

Best bet would be to take the speedo/tranny drive gear to a tranny shop and see what they can do.

Rx-7Doctor

iTrader: (13)

Also see if you have any speedometer shops in the area that recalibrate. In one area I lived in their was a shop that put your car on a dyno roller and re-calibrated by using the applicable gear needed.

LIRX

Good call Doc. That's what mazdatrix told me. I'm suprised that they don't sell speedo gears to match their ring and pinion sets.

LIRX

BTW do you remember how much that cost?

Rx-7Doctor

iTrader: (13)

At the time (2001) the shop charged somewhere around the $30-$35 mark for everything. That included the gear and installation of the gear then they gave a print out of the accuracy of your speedometer.

trochoid

iTrader: (6)

Iirc, Mazda only offers 1 speedo drive gear for all of the 1st gens. They do make other drive gears with a diiferent teeth count for other models depending on tranny and diff gears. I do believe they are all interchangeable.

LIRX

Thanks.
Has anyone done this gear swap and changed their speedo gear?

Rx-7Doctor

iTrader: (13)

Might want to pm wackyracer he has done this swap before.

LIRX

Good idea, I will.

Siraniko

iTrader: (13)

I took the speedo gears out of the KIA also except I misplaced them. My speedometers are off also so I just go with the flow of traffic. Besides, 4.78 gear is boring @ freeway.

mustanghammer

iTrader: (3)

The best way to calibrate your speedometer with this big of a change would be to use a ratio adapter. A ratio adapter is a very small gear box (a little bigger than a couple of match boxes) that is mounted between your speedo cable and the transmission. Assuming that you retained the stock tire diameter (approx 23") then a ratio adapter can be made to compensate for the percentage change in final drive. Or you can do a simple mileage error calculation - drive five miles using mile markers to gauge actual distance and compare it to the mileage recorded on your car's odometer. A speedometer shop can build a ratio adapter for you based on the error you see on your odometer. Once mileage is recorded accurately you speedometer will be accurate too.

To see a picture of a ratio adapter - http://www.a1electric.com/speedometer.htm

Scroll down

Vashner

Just find one of those roadside radars that tell you your speed. Hit it at a few speeds and note the settings.

Super Ghetto non fix. (just kidding but it's not bad to test calibration).

orion84gsl

iTrader: (5)

haha I do that in my Freightliner, because my boss put taller tires on it. At 62 on the dial I'm only doing 60

LIRX

Thanks for the info guys. It's appreciated.