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  1. #1

    Default Need help identifying 99 suburban front differential

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    The picture on left is the one the salvage yard says is supposed to be in my truck according to build code. The middle picture is of the front Diff I just removed. The one on the right has both picture with arrows pointing to the differences.


    Build code says GT4 which is 373 ratio. Got used one from salvage yard and they claim it should match my build code however it is different. My unit only has one plug for the motor that switches the front diff but the replacement one has 2 plugs. One to a motor housing and the other to something that looks like a sensor. Of some sort. Any help in identifying would be appreciated. They are definately different.
    Last edited by Johndavidrichards; 11-14-2011 at 02:44 PM. Reason: added pictures

  2. #2

    Default Help a brother out. Anyone?



    Can anyone help

  3. #3

    Default

    One out of your truck is a 8.25" IFS front differential. I just rebuilt mine out of my 2002 silverado, has exact same connection. You can screw off the plastic actuator on the one on your truck. I would stick with one that is from your truck. What is wrong with yours?
    www.youtube.com/ippielb
    2002 Chevrolet Silverado 1500 z71 1985 Chevrolet Silverado k10 2006 Chevrolet Silverado 2500hd 6.6l LLY Duramax
    6.5" BDS Suspension Lift Edelbrock Carb & Polished Intake Manifold & Valve Covers NAPC Race Transmission & NAPC Built Transfer Case
    EFI Live Comp Cam and Valvetrain Snow Performance Methanol Injection
    35" Toyo Open Country Mud Terrain on 18" Ion Alloy 179's Headman Long Tube Headers and True Dual Exhaust FASS 150gph Titanium Series Pump
    AirAid Cold Air Intake with K&N Dry Filter & AirAid PowerAid Throttle Body Spacer 2" Suspension Lift 33x12.50r15 Tires EFI Live & AFE Stage 2 Intake
    Pacesetter Long Tube Headers with Cats Gone True Dual Exhaust FlowPro 3.73 Gears Yukon Grizzly Locker with Mag-Hytec Cover & Traction Bars
    NGK Iridium Tips & MSD Ignition Plug Wires Baja Spare Tire Holder 33x13.5 Hankook rt03 18" XD Rims
    Innovate LC-1 Wideband o2 Sensor x2 HID's all around LED taillights and 3rd brake light
    BDS Dual Steering Stabilizers Pioneer Double-DIN Touchscreen Navigation with Two 10" Subs under rear seat
    Electric Fan Autometer Pressure, Boost, and Pyro Gauges
    4.56 Gears Airlift Air Bag Suspension

  4. #4

    Default

    Thank you so much for the reply.

    My front diff is making a low grinding noise. Not real bad but you can hear it while slowing down from 50 mph and less.

    I'm planning a 700 mile trip each way back to Maryland and wanted to fix it before I left.


    If I can tell the salvage yard what I need I'm sure they can get it for me. I was just trying to confirm the following I guess:

    1. Is the one removed from my suburban the original front diff or was it swapped before I bought it to a newer one.

    2. Is the salvage yard wrong and what they gave me is not intended for a 1999 suburban?

    3. Assuming both above are correct then maybe I need to ask for a front differential for a later model silver?

    4. Rebuilding an option. I have a guy that can help me crack my old case open and see if it's just som bearings that we can replace.

    I really need to find a 1999 suburban in a parking lot and craw under for a look at someone elses.

    The question is do all 1999 k1500 suburbans have a front diff with one plug or do they have 2 plugs.

    Thanks

  5. #5

    Default

    Quote Originally Posted by Johndavidrichards View Post
    1. Is the one removed from my suburban the original front diff or was it swapped before I bought it to a newer one.
    The one you removed is the original.
    2. Is the salvage yard wrong and what they gave me is not intended for a 1999 suburban?
    Yes, I believe the one the that the wrecker supplied you with is from a 1998 body style suburban.
    3. Assuming both above are correct then maybe I need to ask for a front differential for a later model silver?
    You can ask for a front differential from 99-06 that has the same gear ratio as your suburban, i would recommend going 04+ as they have fixed a breather line problem and you can use synthetic fluids.
    4. Rebuilding an option. I have a guy that can help me crack my old case open and see if it's just som bearings that we can replace.
    You can easily crack open your case yourself! Since you have it off already you've gotten half the battle done! Drain the fluid, and then just unbolt the two halves together, and convince the two halves to separate.
    The question is do all 1999 k1500 suburbans have a front diff with one plug or do they have 2 plugs.
    To my knowledge the 99+ all have the one plug.
    My replies in RED.

    Here's my differential from my 2002 silverado





    In all reality, this is what could be causing a humming or grinding, or if your gears are not set up properly, one of the locking tabs could have broken and set the backlash off and set the pattern crazy.

    I also had a bad bearing or two. Be sure to get your fluids changed!
    www.youtube.com/ippielb
    2002 Chevrolet Silverado 1500 z71 1985 Chevrolet Silverado k10 2006 Chevrolet Silverado 2500hd 6.6l LLY Duramax
    6.5" BDS Suspension Lift Edelbrock Carb & Polished Intake Manifold & Valve Covers NAPC Race Transmission & NAPC Built Transfer Case
    EFI Live Comp Cam and Valvetrain Snow Performance Methanol Injection
    35" Toyo Open Country Mud Terrain on 18" Ion Alloy 179's Headman Long Tube Headers and True Dual Exhaust FASS 150gph Titanium Series Pump
    AirAid Cold Air Intake with K&N Dry Filter & AirAid PowerAid Throttle Body Spacer 2" Suspension Lift 33x12.50r15 Tires EFI Live & AFE Stage 2 Intake
    Pacesetter Long Tube Headers with Cats Gone True Dual Exhaust FlowPro 3.73 Gears Yukon Grizzly Locker with Mag-Hytec Cover & Traction Bars
    NGK Iridium Tips & MSD Ignition Plug Wires Baja Spare Tire Holder 33x13.5 Hankook rt03 18" XD Rims
    Innovate LC-1 Wideband o2 Sensor x2 HID's all around LED taillights and 3rd brake light
    BDS Dual Steering Stabilizers Pioneer Double-DIN Touchscreen Navigation with Two 10" Subs under rear seat
    Electric Fan Autometer Pressure, Boost, and Pyro Gauges
    4.56 Gears Airlift Air Bag Suspension

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