I have an 8.8 question...

Discussion in 'Other Automotive Tech & Talk' started by 71gold, Dec 28, 2016.

  1. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,456
    Likes Received:
    2,835
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    I was told that changing the gear ratio in a Ford 8.8 will not change the speedo reading. something about the reluctor gear reads the same... anyone agree/disagree?

    2010 8.8 stock size tires...3:73 to 4:10...5 speed auto
     
  2. RASelkirk

    RASelkirk Retired!

    Joined:
    Jan 10, 2008
    Messages:
    1,393
    Likes Received:
    57
    Trophy Points:
    143
    Location:
    Port Neches, TX
    Vehicle:
    Sonic Blue '72 w/LS-1, 200R4, 9" w/3.50
    Can't see it. Changing the gear will make the reluctor run at a different RPM for the same speed. Maybe your"info source" failed to mention you need a change in ECM programming to even things out?

    Hmmm, on second thought... The reluctor is tied to wheel speed (ring gear), so maybe that is correct!
     
  3. Earl Branham

    Earl Branham Certified Old Fart

    Joined:
    Mar 9, 2002
    Messages:
    6,367
    Likes Received:
    200
    Trophy Points:
    218
    Garage:
    1
    Location:
    Lugoff, SC
    Vehicle:
    '69.5 Maverick 302, T-5, Grabber Green
    No clue.......you kill your 8"?
     
  4. RMiller

    RMiller My name is Rick

    Joined:
    Dec 12, 2009
    Messages:
    4,124
    Likes Received:
    1,154
    Trophy Points:
    523
    Garage:
    1
    Location:
    Kennewick, WA
    Vehicle:
    1971 Maverick Grabber
    Sounds right, the 8.8 reluctor wheel is bolted to the differential with the ring gear. The only thing that will change it's speed in relation to ground speed is tire size.
     
  5. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,456
    Likes Received:
    2,835
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    nope...it's in Effie's new ride...:drive:...:chirp:
     
  6. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,456
    Likes Received:
    2,835
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    I did a little searching and couldn't find ant different reluctor wheels...:huh:
     
  7. RASelkirk

    RASelkirk Retired!

    Joined:
    Jan 10, 2008
    Messages:
    1,393
    Likes Received:
    57
    Trophy Points:
    143
    Location:
    Port Neches, TX
    Vehicle:
    Sonic Blue '72 w/LS-1, 200R4, 9" w/3.50
    I'd assume the gear "ratio" change is done with a software edit...
     
  8. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,456
    Likes Received:
    2,835
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    ...:huh:...
     
  9. Earl Branham

    Earl Branham Certified Old Fart

    Joined:
    Mar 9, 2002
    Messages:
    6,367
    Likes Received:
    200
    Trophy Points:
    218
    Garage:
    1
    Location:
    Lugoff, SC
    Vehicle:
    '69.5 Maverick 302, T-5, Grabber Green
    Effie's new ride......did she get an old car?
     
  10. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,456
    Likes Received:
    2,835
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    nope...
     
  11. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,456
    Likes Received:
    2,835
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    here is what I know so far...will add more as I hear it.

    1. nothing needs to be changed.
    2. need to do a tune.
    3. need to change the gear drive to a different tooth count.
     
  12. MaverickDan

    MaverickDan I wanna go fast!!!

    Joined:
    Jan 1, 2007
    Messages:
    808
    Likes Received:
    45
    Trophy Points:
    113
    Garage:
    1
    Location:
    Midlothian, VA.
    Vehicle:
    73 Maverick 4dr
    A gear change on an 8.8 does not require a speedo recalibration if using the speed sensor in the housing. Only time a recalibration is needed is if you change tire size. The speed of the ring gear doesnt change at a given speed no matter what gear is in it. I changed from a 3:08 to 3:55 in my 95 f150, speedometer still accurate.
     
    71gold likes this.

Share This Page