Speedometer recalibation

Discussion in 'General Discussion' started by Codyhurly64, May 20, 2013.

  1. Codyhurly64

    Codyhurly64 New Member

    This weekend I'm putting a body lift on my truck along with a set of 33x12.50r15 swampers! How far off do you think my speedometer will be? Is there any cheap way to recalibrate it? Thanks!
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  3. Shawn

    Shawn Cranky old man

    On my 97 Ranger I swapped 15" tires for the orig 14". I went to Ford and got a different gear for in the transmission. It was $10.00 or less. Maybe get a gear for a Ranger with 16 inch rims. Some Rangers had 255/70/16 tires.
    Last edited: May 20, 2013
  4. OP

    Codyhurly64 New Member

    There is no way I'm tearing out the tranny in that sucker! haha
  5. Shawn

    Shawn Cranky old man

    Last edited: May 20, 2013
  6. Scrambler82

    Scrambler82 Old Guy User

    I put 33s on my truck with 4.10s.

    At 40 and below mph I don't see a lot of difference at 60 up I see about 2 mph higher speeds.

    I don't think there will be enough different cue unless you started with 29" tires.
  7. Shawn

    Shawn Cranky old man

    There are a lot of tire size calculators on the net to figure the exact difference. Or you can use a GPS and see the actual speed. My trip minder has a speed output that I have corrected for my larger tires. My speedo is off because I replaced the 235/75/15's with 215/85/16's.
    I also have a Canada speedo that the main scale is KM. It's off about 5% with the larger tires. It goes to 200 and looks cool....It has a mph scale, but its small and easier for me to read the trip minder.
  8. rwenzing

    rwenzing Bob

    The speedo gear swap only applies to 97 and earlier. OP has a 98.

    1998~2000 Ranger

    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.
    Adjustment Method: (4WABS trucks): flash adjustment in the 4WABS Module using a dealer tool such as NGS+. WDS, IDS may also work.
  9. Shawn

    Shawn Cranky old man

    Well in that case, try this.

    Or if you go to a dealer...I stole this info from the web.

    This is about Full size Fords but it may help.

    tell ford tech.to go to special service message 11789 and 11790. OASIS will spell it right out.this is from a guy who took delivery with 295's on.there was some caution for an auto trans.if a tech gives you a hard time tell them circumference is 2pi times the radius.... 2pi[r]....pi=3.1416.

    33.5's have 621 revolutions per mile. Ford will need to know this...Mickey Thompson website

    Last edited: May 21, 2013

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