1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Speedometer reads about 10% faster

Discussion in '1st Gen. Tacomas (1995-2004)' started by ZrowGz, Apr 9, 2018.

  1. Apr 9, 2018 at 9:54 PM
    #1
    ZrowGz

    ZrowGz [OP] I'm a n00b.

    Joined:
    Nov 18, 2017
    Member:
    #236303
    Messages:
    507
    Gender:
    Male
    SLC, UT
    Vehicle:
    97 4x4 LT/Cantilever
    Compared to GPS, my speedo reads high.
    1997 taco that had been regeared to 4.88
    What is the part that I need to swap in to get it reading accurately. It also has 33" or 32" tires on it...
    Anyone have a link to a thread that illustrates it better?
    Thanks!
     
  2. Apr 9, 2018 at 10:00 PM
    #2
    tony2018

    tony2018 Well-Known Member

    Joined:
    Feb 24, 2014
    Member:
    #123866
    Messages:
    5,303
    Gender:
    Male
    That is fuckin awesome.
     
  3. Apr 10, 2018 at 4:25 AM
    #3
    nzbrock

    nzbrock Well-Known Member

    Joined:
    Jan 6, 2013
    Member:
    #94572
    Messages:
    2,579
    Gender:
    Male
    First Name:
    Noah
    San Marcos, TX
    Vehicle:
    99 TRD Prerunner 3RZ
    SAW 2.0 Coilovers Wheeler's 5 Leaf + 3 AAL Bilstein 5100s LCE long tube header Flowmaster Delta 50 Muffler FJ Trail Team Wheels 255/85/16 Cooper ST Maxx 4Runner overhead sunglass console 4Runner leather seats All LED lights Red/Clear Tail Light Tundra Brakes HID Projector Retrofits 4Runner Auto Up/Down Windows Bullet Liner Cargo tie down system E-locker axle swap w/4.56 Gears ARE MX Cap Prinsu Toprac Custom heated turn signal/puddle light mirrors Volant Intake Tube
    You can swap the speed sensor gear for one with a different amount of teeth. On 4WD trucks it is located on the transfer case. On 2WD trucks it is located on the transmission.
    I used this thread as a reference: https://forum.ih8mud.com/threads/speedometer-correction-by-t-case-gear-change.480939/

    Since yours is a 97 it may have a mechanical speedometer cable. If so, look at the charts in that thread and only look at ones that use a mechanical cable.
     
  4. Apr 10, 2018 at 6:17 AM
    #4
    onakat

    onakat Well-Known Member

    Joined:
    Jul 2, 2016
    Member:
    #191075
    Messages:
    1,607
    Gender:
    Female
    Canada
    Vehicle:
    2000 indestructaco!
    your speedometer is off because of your bigger tires (and maybe the regearing itself)
    use the tire size calculator and do some experiments:
    https://www.tacomaworld.com/tirecalc
     
  5. Apr 10, 2018 at 7:03 AM
    #5
    turbodb

    turbodb AdventureTaco

    Joined:
    Feb 9, 2016
    Member:
    #177696
    Messages:
    5,990
    Gender:
    Male
    First Name:
    Dan
    PNW
    Vehicle:
    2000 Tacoma Xcab 4x4 SR5 V6 TRD
    AdventureTaco
    Here are a couple links that will help you out. The part number you need is likely a speedo gear.

    Why your speed is off:
    Speedometers, Odometers, and Gas Mileage - All Lies!

    How to fix it:
    Replacing the Speedo Gear
     
    Last edited: Apr 10, 2018
  6. Apr 10, 2018 at 7:16 AM
    #6
    ZrowGz

    ZrowGz [OP] I'm a n00b.

    Joined:
    Nov 18, 2017
    Member:
    #236303
    Messages:
    507
    Gender:
    Male
    SLC, UT
    Vehicle:
    97 4x4 LT/Cantilever
    Excellent! Thank you. I'll take a look through these.

    Yep it is a mechanically driven Speedo with 4wd. The larger tires would make it read slower than real speed while the rehearsal would make it read fast I believe.

    So yeah I think I just need a great. Just wasn't sure what her it would be and how to find the part number and where to buy it. Looks like I should be able to figure it out from those links!
     
  7. Apr 10, 2018 at 8:10 AM
    #7
    boostedka

    boostedka Well-Known Member

    Joined:
    Sep 29, 2011
    Member:
    #64367
    Messages:
    5,276
    Gender:
    Male
    First Name:
    James
    NM
    Vehicle:
    2004 4Runner
    ZrowGz [OP] likes this.
  8. Apr 10, 2018 at 8:40 AM
    #8
    nzbrock

    nzbrock Well-Known Member

    Joined:
    Jan 6, 2013
    Member:
    #94572
    Messages:
    2,579
    Gender:
    Male
    First Name:
    Noah
    San Marcos, TX
    Vehicle:
    99 TRD Prerunner 3RZ
    SAW 2.0 Coilovers Wheeler's 5 Leaf + 3 AAL Bilstein 5100s LCE long tube header Flowmaster Delta 50 Muffler FJ Trail Team Wheels 255/85/16 Cooper ST Maxx 4Runner overhead sunglass console 4Runner leather seats All LED lights Red/Clear Tail Light Tundra Brakes HID Projector Retrofits 4Runner Auto Up/Down Windows Bullet Liner Cargo tie down system E-locker axle swap w/4.56 Gears ARE MX Cap Prinsu Toprac Custom heated turn signal/puddle light mirrors Volant Intake Tube
    These are your options taken from here: https://forum.ih8mud.com/threads/speedometer-correction-by-t-case-gear-change.480939/page-2

    33482-39135 18 tooth, 18x6 mark RN10*/RN110/RN13*
    33482-39025 19 tooth, 19x6 mark TCR1*
    33482-39045 20 tooth, 20x6 mark RN106/RN110/RN13* (ATM)

    33403-39345 31 tooth, 31x11 mark RN131 (ATM)
    33403-19255 32 tooth, 32x11 mark RN10*/RN110/RN13*
    33403-29115 33 tooth, 33x11 mark VZN10*/VZN110/VZN13*

    You need to determine your stock gear by plugging your VIN into ToyoDIY.com. You can search for "speedometer driven gear" once you have your VIN plugged in. You also need to know the stock tire size and gearing so that you can calculate the change in ratio based on your new tire size and gearing.

    I believe if you have to stay with whatever "mark" you have stock.

    If your speedo reads fast, that means your current speedo gear is too small and is spinning to fast. You need to replace it will a larger gear.

    If your speedo reads slow, that means your current speedo gear is too large and spinning too slow. You need to replace it with a smaller gear.
     
  9. Apr 11, 2018 at 10:51 AM
    #9
    shawnster88

    shawnster88 Well-Known Member

    Joined:
    Aug 19, 2012
    Member:
    #85096
    Messages:
    326
    Gender:
    Male
    First Name:
    Shawn
    Panhandle Florida
    Vehicle:
    96 Tacoma Reg cab 2.7 5 speed
    OME 881 coil springs, OME nitrocharger sport shocks front and rear. Nitro 4:56 gears. ARB rear locker. Shrockworks front bumper with Warn M8000S winch.
    Great info!!! My speedo is showing 65 when I’m really going 60 by gps. Stock set up was 3:58 gears and 225/75/15. Now I have 4:56 gears and 265/75/16 tires. I have the 30 tooth speedo gear in the diff. I know I’ll need bigger since my speed is showing higher. How can I figure if I’ll need the 31,32, or 33 tooth gear?
     
  10. Apr 11, 2018 at 11:07 AM
    #10
    nzbrock

    nzbrock Well-Known Member

    Joined:
    Jan 6, 2013
    Member:
    #94572
    Messages:
    2,579
    Gender:
    Male
    First Name:
    Noah
    San Marcos, TX
    Vehicle:
    99 TRD Prerunner 3RZ
    SAW 2.0 Coilovers Wheeler's 5 Leaf + 3 AAL Bilstein 5100s LCE long tube header Flowmaster Delta 50 Muffler FJ Trail Team Wheels 255/85/16 Cooper ST Maxx 4Runner overhead sunglass console 4Runner leather seats All LED lights Red/Clear Tail Light Tundra Brakes HID Projector Retrofits 4Runner Auto Up/Down Windows Bullet Liner Cargo tie down system E-locker axle swap w/4.56 Gears ARE MX Cap Prinsu Toprac Custom heated turn signal/puddle light mirrors Volant Intake Tube
    You can either calculate it by using exact gear ratio to tire size changes, or more simply by using the speedo gear and mph. The gears and tires will probably be more accurate, but you only have a couple options to choose from as far as speedo gears go.

    1 - (60/65) =~8%
    therefore you need a speedo gear that is ~8% larger.

    1 - (30/33) =~9% is probably as close as you're going to get.

    Also, keep in mind that your stock speedometer is usually off by a certain amount. Sometimes you can actually get it more exact when changing the gear after changing your differential gears and tires.
     
  11. Apr 11, 2018 at 12:02 PM
    #11
    shawnster88

    shawnster88 Well-Known Member

    Joined:
    Aug 19, 2012
    Member:
    #85096
    Messages:
    326
    Gender:
    Male
    First Name:
    Shawn
    Panhandle Florida
    Vehicle:
    96 Tacoma Reg cab 2.7 5 speed
    OME 881 coil springs, OME nitrocharger sport shocks front and rear. Nitro 4:56 gears. ARB rear locker. Shrockworks front bumper with Warn M8000S winch.
    Awesome...I didn’t even know this could be done. Thanks for the info!!!
     
  12. Apr 11, 2018 at 12:24 PM
    #12
    se7enine

    se7enine MCMLXXIX

    Joined:
    Apr 18, 2013
    Member:
    #102322
    Messages:
    20,746
    Gender:
    Male
    Reno, NV
    Vehicle:
    98 Tacoma SR5 Xtra Cab 3.4L
    I planned on doing this but after I adjusted my scangauge to compensate I kinda didn't bother. Still oughta though.
     
  13. Apr 11, 2018 at 4:36 PM
    #13
    Vision10

    Vision10 Well-Known Member

    Joined:
    Sep 24, 2017
    Member:
    #230990
    Messages:
    115
    Gender:
    Male
    First Name:
    Logan
    Oklahoma
    Vehicle:
    2001 2wd 2.4l auto sst
    Camper, grill, backup camera, stereo/speakers,
    Mine does the exact same thing
     
  14. Apr 12, 2018 at 10:24 AM
    #14
    dougfrye

    dougfrye Member

    Joined:
    Feb 24, 2015
    Member:
    #149524
    Messages:
    9
    Gender:
    Male
    First Name:
    Doug
    Olympia
    Vehicle:
    1998 3RZ SR5
    OME 880, Blistein 5100 all 4 corners, General Springs HD on the rear, re gear to 4.56, Falkon Wildpeak A/T3W 265 75 16, 3RZ Long block from NW Team Yota
    I just had my 1998 regeared with 4.56 nitro gears and my tires are 265 78 16. I replaced the speedo gear with the 33 tooth and now the all is with in 1MPH. Truck 2.7 with manual 5 speed.
     
    shawnster88 likes this.
  15. Apr 12, 2018 at 10:29 AM
    #15
    dougfrye

    dougfrye Member

    Joined:
    Feb 24, 2015
    Member:
    #149524
    Messages:
    9
    Gender:
    Male
    First Name:
    Doug
    Olympia
    Vehicle:
    1998 3RZ SR5
    OME 880, Blistein 5100 all 4 corners, General Springs HD on the rear, re gear to 4.56, Falkon Wildpeak A/T3W 265 75 16, 3RZ Long block from NW Team Yota
    Make that 265 75 16 Falken Wildpeak AT3W
     

Products Discussed in

To Top