Question about 1985 Ford Thunderbird

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Bird Rear-end Size

What size rear-end is in a 1985 T-Bird Turbo Coupe? What gear ratio? Would it be an equal lock?

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Hi meduck4,heres what you need brother as I cant see your diff, 3 ways to tell what you have:
#1 The first is the driver's door tag; there will be a one-letter or one-numeral axle code listed there. You can then compare it to the chart below: CODE Rear Axle Ratio Conventional Locking 8 M 2.73 Y Z 3.08 F R 3.45 5 E 3.27 6 W 3.73
#2 The second is the axle tag, attached to the lower lefthand bolt on the rear axle itself. The bottom left line will give you the gear ratio, and the type of rear end (S for limited slip non-locking, and L for locking).

#3 The 7.5" rear axle height is shorter than the width and the shape appears "oval".
The 8.8" rear axle
dimensions are equal and the shape appears "round".

This will tell you what you have my friend,good luck

Posted on Nov 13, 2008

  • mike harris
    mike harris Nov 13, 2008

    Hey meduck the chart for #1 didnt work here it is again:

    CODE
    CONVENTIONAL LOCKING REAR AXLE RATIO
    8 M 2.73
    Y Z 3.08
    F R 3.45
    5 E 3.27
    6 W 3.73



  • mike harris
    mike harris Nov 13, 2008

    THIS FORMAT IS A PAIN ONCE MORE MY FRIEND #1 METHOD CHART
    Code
    Conventional Diff: 8, Y, F , 5 , 6
    Locking Diff : M, Z, R, E , W
    8 and M is a 2.73, Y and Z is a 3.08, F and R is a 3.45, 5 and E is a 3.27,6 and W is a 3.73

    wow that was a lot of work hope you understand good luck to you if you have any question I would be glad to help


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