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  1. #1
    Sr. Apprentice socal77k5's Avatar
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    Default 1987 rear diff gear swap?

    ok heres what i got going on, i have a 87 suburban, i bought it as a running project and thats exactly what i got, its lifted 4 inches, on 33 inch tires, and it drives like ****, runs well but drives horrible. it takes me a while to get up to 45 50 miles an hour. and wont go over 55 or so. im figuring i need a diff gear swap probably to 4:56? my question is how hard would this be to do myself? i know someone selling a gm 14 bolt 456 gears, how hard would it be for me to put this in my rear diff. i disconnected my front drive shaft because the guy who put on the lift didnt do anything to the shaft or trans so it doesnt reach. the front lift is horrible, 4 inch block (illegal) and theres only 2 leafs per side. the shock hoops cracked and broke off due to this **** lift. rear lift is fine. so anyone on here know how to swao gears maybe help me out with a step by step?
    1987 Chevy Suburban 4x4 - Lifes a garden, dig it, gotta keep on keepin on!


  2. #2
    Legend Mean_Green_95's Avatar
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    Default

    If you've never done gears before, pay a professional to do it. It's very easy to screw up the gears and blowing up the diff.
    2010 Equinox LT
    2.4, 6 speed auto, power lift gate, remote start, bluetooth, xm.

    1995 Cheyenne C1500 ext. cab(my baby, my first truck)
    5.0, 5 speed, Silverado appearance package, power nothing, bucket seats and console Silverado, painted black interior, eBay halo headlights, eBay chrome tails, eBay cai, dual Flowmaster 40's w/no cats, 15x7 American Racing Hopsters, Walmart fog lights, SS mirrors

  3. #3

    Default

    Why not swap over the whole axle and alleviate the problem of trying to set-up the gears properly?

  4. #4
    Sr. Apprentice socal77k5's Avatar
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    Default

    thanks ill have to do that. maybe imight just drop the lift 2 inches, and throw on some smaller tires. ok so lift is ****, if i drop teh lift 2 inches would that take care of teh power problem?
    1987 Chevy Suburban 4x4 - Lifes a garden, dig it, gotta keep on keepin on!


  5. #5

    Default

    If you drop the tire size it might, depends on gear ratio though.
    With Suburbans its always best to keep tham as low as possible, their like big sails going down the road and any help in the profile department improves drag.

  6. #6
    Sr. Apprentice socal77k5's Avatar
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    yeah im trying to find out what the 1987 suburbans stock gear ratio is, cause im pretty sure the previous owner didnt change it when he thew on the lift, so i plan on swapping the 4 inch lift for a 2 inch lift and throwing on 31s or 30s to best fit teh gear ratio.
    1987 Chevy Suburban 4x4 - Lifes a garden, dig it, gotta keep on keepin on!


  7. #7
    Legend

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    your stocks should be 3.73 or 4.10, but if your truck is struggling with only a four inch lift and 33s then i dont think that a gear change will help, this sounds like a bigger problem. Stock gears from that genereation should be handling your 33s just fine. i have 3.73 on my 99 and going up to a 33 mad almost no difference on the stock gears
    99 K1500 Suburban LT "THE BEAST"
    Hypertech III, K&N, true dual
    285/75/16
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  8. #8
    Sr. Apprentice socal77k5's Avatar
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    thats what i was thinking too, i am thinking its more along the line of the lift and the trans, i noticed today when i lifted teh truck on a hydrolic lift, and had the motor running, that the torque converter looks like it has pressure on it and causeing it to wobble, now if the guy did a shotty job on the lift could that put the trans at a bad angle and cause lack there of power?
    1987 Chevy Suburban 4x4 - Lifes a garden, dig it, gotta keep on keepin on!


  9. #9
    Legend

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    It could be binding things up that is for sure.
    99 K1500 Suburban LT "THE BEAST"
    Hypertech III, K&N, true dual
    285/75/16
    ___________________________
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  10. #10
    Sr. Apprentice socal77k5's Avatar
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    Quote Originally Posted by vncj96 View Post
    It could be binding things up that is for sure.
    yeah i think thats whats going on, i think the guy did a horrible lift job. the torque converter looks like a football being thrown just wobbly as hell. if i go easy on the gas pedal it will shift perfectly, but if i step on it, it will bog and not shift until i let go of the gas pedal
    1987 Chevy Suburban 4x4 - Lifes a garden, dig it, gotta keep on keepin on!


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