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Topic: Speedometer (Read 1549 times) previous topic - next topic

Speedometer

I am going to change tire size, rear axle, and speedometer to buttstuffogue. I know that there will quite a change and I will need to correct my speedometer for correct MPH. From what I understand, I will need to change a small gear at my transmission. What is the proper procedure for this task? Thanks!

Speedometer

Reply #2 –
Quote from: 88xr7cougar;413828
First for Speedo correction for gear use this site.http://www.bgsoflex.com/speedo1.html.

Thanks! I'm going to put my new gauges in, power windows, door locks, and heater core in at the same time. From what I have read, going from 2.75 to 3.45 gears will really throw off my speedometer.

Speedometer

Reply #3 –
It will. Keep in mind that there are a couple different gears inside the transmissions....they're not really interchangeable. I put an AOD speedo drive gear in my T5 and wrecked it (the plastic gear) pretty quickly.

Use the chart to determine what ya need...the drive gears can be had on ebay and even a Ford dealership for a few bucks. They had to order mine for me, but it was in stock in about 4 days.

Let us know what ya come up with.
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

Speedometer

Reply #4 –
Quote from: ThunderbirdSport302;413834
It will. Keep in mind that there are a couple different gears inside the transmissions....they're not really interchangeable. I put an AOD speedo drive gear in my T5 and wrecked it (the plastic gear) pretty quickly.

Use the chart to determine what ya need...the drive gears can be had on ebay and even a Ford dealership for a few bucks. They had to order mine for me, but it was in stock in about 4 days.

Let us know what ya come up with.

I just had the transmission rebuilt with a shift kit. I might just finish up my car and take it back to them and let them set it up to be safe.

Speedometer

Reply #5 –
One tooth on the driven gear equals app 5-7 MPH

:burnout:
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

Speedometer

Reply #6 –
Well that would explain why mine is 7 MPH off then lol.
88 Turbocoupe: Coast High Performance 331 kit 28oz balance, Comp XE264HR14 cam, 58cc 185 afr heads, 1.7 roller rockers, Mass-Flo EFI (was POS to setup and their techline is a joke at best)
Full 1 5/8 primary equal length headers, 2 1/2 exhaust, Full manual reverse VB c4 and baked off clear coat "BECAUSE RACECAR"

Speedometer

Reply #7 –
When I was doing the powertrain/running gear swap on the new Bird, I ran the car for 2 days before swapping the 2.73 rear end out for the 3.73 rear from the other car.  My AODW had the speedo gear swapped to suit the 3.73 rear, but with the 2.73, the speedo was off by somewhere like 15 mph at 60 according to GPS, IIRC.

Speedometer

Reply #8 –
That is about what I have read. If I'm doing 80 mph on the freeway, my speedometer will be about 15 mph off going from 2.73 to 3.45 rear gears. I'm also going to buy 255/50/16 tires and take half a coil to one coil off my springs, so I need to get all that done before I get the speedo set up. Thanks!