New gears and 35s... Speedo and Odometer way off!!!!
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New gears and 35s... Speedo and Odometer way off!!!!
Ok so my speedo and odometer are way off. My truck is a 95 with the 4.0 and i have 4.88s with 35x12.5/15. I'm trying to figure out my MPGs and want to keep track of my oil changes and other maintenance. I looked on TRS and counldnt find a calculator. Maybe a tuner of some sort will correct it? Is there a formula for figuring out my correct MPH and miles?
Thanks!
Thanks!
#2
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I think the tires are 225/70/14 so that's about 26" and 3.08s
#6
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On a 95 it probably has a mechanical speedo cable, not positive though. If it does have one you need to change the gear on the end of the cable that goes into the transmission tail housing. There is an equation on TRS to help you calculate the proper amount of gear teeth.
#8
i forget the formula, its been so long since i've used it. its like origional tire diameter/new tire diameter.. then multiply that against the calculation of the fuel mileage? i dont remember.
i still don't get your truck.. EVERY lifted truck i've rode in says its going slower than it is.
i still don't get your truck.. EVERY lifted truck i've rode in says its going slower than it is.
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Im looking for the cheapest way to try and fix this im pretty broke right now.
#14
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Universal Speedometer Signal Interface
I would recommend that you read the Superlifts' Truspeed instructions for the install, very similar, and you will find what wires to tap into easier. The SGI-5 is universal so it will take some toying around with it to get it right. But it works very well.
#16
#18
This was changed several times and can be very confusing. Here's a listing of the different speedo systems as I understand them:
94 and earlier:
Traditional cable-driven speedometer/odometer
Adjustment Method: interchangeable gears at transmission or transfer case
Adjusts for: axle ratio and tire diameter.
95~97
Electric speedometer geared to odometer
VSS source: gear driven pulse generator on the trans or t-case
VSS wire to speedometer: Gray/Black
Adjustment Method: interchangeable gears at transmission or transfer case
Adjusts for: axle ratio and tire diameter.
98~2000
Electric speedometer geared to odometer
Raw VSS source: the ABS sensor on the rear diff housing reads the tone ring.
Corrected VSS Wire to speedometer: Gray/Black
Adjustment Method: (RABS trucks): flash adjustment in the Generic Electronic Module (GEM) using a dealer tool such as NGS+. WDS, IDS may also work.
ADJ Method: (4WABS trucks): flash adjustment in the 4WABS Module using a dealer tool such as NGS+. WDS, IDS may also work.
Adjusts for: tire diameter only.
2001~2003
Electric speedometer geared to odometer
Raw VSS source: Output Shaft Speed sensor fits into a window in the transmission extension housing where it reads a toothwheel machined on the output shaft.
Corrected VSS Wire: Gray/Black
Adjustment Method: flash adjustment in the Powertrain Control Module (PCM) using an aftermarket flash tool. Dealer tools such as NGS+, WDS, IDS may also work BUT the adjustment range is probably factory limited by VIDBLOCK.
Adjusts for: axle ratio and tire diameter.
2004~2006
Cluster microprocessor controls speedometer and digital odometer
Raw VSS source: Output Shaft Speed sensor fits into a window in the transmission extension housing where it reads a toothwheel machined on the output shaft.
Corrected VSS Wire to cluster: Gray/Black
Adjustment Method: flash adjustment in the Powertrain Control Module (PCM) using an aftermarket flash tool. Dealer tools such as NGS+, WDS, IDS may also work BUT the adjustment range is probably factory limited by VIDBLOCK.
Adjusts for: axle ratio and tire diameter.
2007~2009 (Unconfirmed)
Cluster microprocessor controls speedometer and digital odometer
Raw VSS source: Output Shaft Speed sensor fits into a window in the transmission extension housing where it reads a toothwheel machined on the output shaft.
Corrected VSS to cluster: Transmitted from PCM over Module Communications Network
Adjustment Method: flash adjustment in the Powertrain Control Module (PCM) using an aftermarket flash tool. Dealer tools such as NGS+, WDS, IDS may also work BUT the adjustment range is probably factory limited by VIDBLOCK.
Adjusts for: axle ratio and tire diameter.
94 and earlier:
Traditional cable-driven speedometer/odometer
Adjustment Method: interchangeable gears at transmission or transfer case
Adjusts for: axle ratio and tire diameter.
95~97
Electric speedometer geared to odometer
VSS source: gear driven pulse generator on the trans or t-case
VSS wire to speedometer: Gray/Black
Adjustment Method: interchangeable gears at transmission or transfer case
Adjusts for: axle ratio and tire diameter.
98~2000
Electric speedometer geared to odometer
Raw VSS source: the ABS sensor on the rear diff housing reads the tone ring.
Corrected VSS Wire to speedometer: Gray/Black
Adjustment Method: (RABS trucks): flash adjustment in the Generic Electronic Module (GEM) using a dealer tool such as NGS+. WDS, IDS may also work.
ADJ Method: (4WABS trucks): flash adjustment in the 4WABS Module using a dealer tool such as NGS+. WDS, IDS may also work.
Adjusts for: tire diameter only.
2001~2003
Electric speedometer geared to odometer
Raw VSS source: Output Shaft Speed sensor fits into a window in the transmission extension housing where it reads a toothwheel machined on the output shaft.
Corrected VSS Wire: Gray/Black
Adjustment Method: flash adjustment in the Powertrain Control Module (PCM) using an aftermarket flash tool. Dealer tools such as NGS+, WDS, IDS may also work BUT the adjustment range is probably factory limited by VIDBLOCK.
Adjusts for: axle ratio and tire diameter.
2004~2006
Cluster microprocessor controls speedometer and digital odometer
Raw VSS source: Output Shaft Speed sensor fits into a window in the transmission extension housing where it reads a toothwheel machined on the output shaft.
Corrected VSS Wire to cluster: Gray/Black
Adjustment Method: flash adjustment in the Powertrain Control Module (PCM) using an aftermarket flash tool. Dealer tools such as NGS+, WDS, IDS may also work BUT the adjustment range is probably factory limited by VIDBLOCK.
Adjusts for: axle ratio and tire diameter.
2007~2009 (Unconfirmed)
Cluster microprocessor controls speedometer and digital odometer
Raw VSS source: Output Shaft Speed sensor fits into a window in the transmission extension housing where it reads a toothwheel machined on the output shaft.
Corrected VSS to cluster: Transmitted from PCM over Module Communications Network
Adjustment Method: flash adjustment in the Powertrain Control Module (PCM) using an aftermarket flash tool. Dealer tools such as NGS+, WDS, IDS may also work BUT the adjustment range is probably factory limited by VIDBLOCK.
Adjusts for: axle ratio and tire diameter.
#19
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This was changed several times and can be very confusing. Here's a listing of the different speedo systems as I understand them:
95~97
Electric speedometer geared to odometer
VSS source: gear driven pulse generator on the trans or t-case
VSS wire to speedometer: Gray/Black
Adjustment Method: interchangeable gears at transmission or transfer case
Adjusts for: axle ratio and tire diameter.
95~97
Electric speedometer geared to odometer
VSS source: gear driven pulse generator on the trans or t-case
VSS wire to speedometer: Gray/Black
Adjustment Method: interchangeable gears at transmission or transfer case
Adjusts for: axle ratio and tire diameter.
#20
Ford dealer, maybe elsewhere. First, you need to calculate the change in overall ratio from the old and new tire diameter and the old and new axle ratio. Then you need to find out what size gear is in there now. Together, that info will tell you which color gear to buy. There's a chart with part numbers in the TRS tech library.
Last edited by V8 Level II; 09-14-2009 at 08:17 PM.
#23
my 95 is OBD II, but earlier 95's could have OBDI.
did you see this page on TRS?
Ford Ranger/BroncoII speedometer gear change/calibration
did you see this page on TRS?
Ford Ranger/BroncoII speedometer gear change/calibration