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Hummer transmissions & drivetrains repair questions and answers

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  • dbierman13
    dbierman13 - 2008 Hummer H3 - Transmissions & Drivetrains - 5/5/2013
    Leak under rear axle
    I recently noticed a small puddle near the center of the rear end. Upon further inspection, the fluid appears to be engine oil, but is coming from a box under the center of the rear axle. I think this is the rear differential. Is this something that I can fix myself?
    • Jimm
      5/5/2013 Jimm
      It depends on the leak source. As a first step, place a piece of cardboard underneath the rear differential to determine the location of the leak. It could be the axle pinion seal on the front of the differential - just behind where the driveshaft u-joint is located.
      If this seal is leaking, then this is a fairly simple fix. Remove the driveshaft (be sure to place marks on the u-joint and yoke to index the shaft in the same position during the reinstallation). Next, remove the differential center yoke (where the driveshaft rear u-joint is located). Once the yoke is removed, then you can use a seal puller to remove the old pinion seal.
      Clean the seal mating surfaces on the differential, then install the new seal (use a seal install tool) being certain of the seal installation direction. The rest of the installation is the reverse of the removal steps.

      Try the many on-line auto parts sources, such as;, and for the replacement parts. For example, they (RockAuto) list the rear differential pinion seal from around $6.20 for your vehicle.
  • tendayi
    tendayi - 2003 Hummer H2 - Transmissions & Drivetrains - 4/8/2013
    Transmission slips
    My hummer slips when transitioning gears, i got the master overhaul kit from A.R. TRANSMISSION, INC. The thing is i can not seem to get the reaction shell and input planetary set out of the trnsmission . How does one get it out , i an in Ethiopia and noone seem to ...
    • HouseCallAuto
      4/8/2013 HouseCallAuto
      According to a basic lookup in All data on transmission overhaul, there is a retainer that comes off with a snap ring pliers that is described as " the output shaft to input carrier retainer" and after removing that retainer everything comes out without an issue. Remove the input carrier assembly and the bearing assembly. Remove the input internal gear and the reaction carrier shaft assembly. Remove the thrust washer and the reaction sun shell.

      You may find some needed part numbers here in this article which is a TSB for Hummer tranny issue.
  • BiggRob77
    BiggRob77 - 2007 Hummer H3 - Transmissions & Drivetrains - 9/22/2012
    Loud annoying metal rattle under truck.
    It sounds like a heat shield for the catalytic converter but I'm not sure. This rattle happens ONLY between 15mph and 19mph. At 20mph it's totally gone. Also it rattles between these speeds whether your accelerating, decelerating, coasting in gear or even in ...
    • CVO
      9/22/2012 CVO
      It sounds like a heat shield for the catalytic converter or the honey comb inside the cat. If it is the cat, this vehicle is still under the warranty for 8 years or 80 K miles.
      10/6/2012 BiggRob77
      Thanks. I was thinking that myself but it has odd times when the noise happens. I would think that if I was to rev the engine that shield would rattle or make some sort of noise but it doesn't make a sound. I will have crawl under it this weekend and bang around.
  • Serg
    Serg - 2006 Hummer H3 - Transmissions & Drivetrains - 2/9/2012
    What is the difference between EMPI Axles Part#: EMP801525 AND Part#: W0133-1898264
    I am about to replace the Front Axle (passenger side) on my Hummer H3 2006. EMPI offers 2 Axles variations for my Hummer Part#: EMP801525 AND Part#: W0133-1898264. What is the difference between this 2 Axles and which one is better to install?
    • Spoon Sports
      2/9/2012 Spoon Sports
      Unfortunately, the W0133 axle lacks information thus im unable to make any differentiation.

      My suggestion would be to just measure your existing axle and compare it to the specs of the EMP801505
  • Serg
    Serg - 2006 Hummer H3 - Transmissions & Drivetrains - 2/7/2012
    What is better New EMPI Axle OR remanufactured OEM Axle?
    Need to change front axle (passenger side) on my Hummer H3, 2006. What is better to use, EMPI new Axle or remanufactured OEM Axle?
  • Chubbs
    Chubbs - 2006 Hummer H3 - Transmissions & Drivetrains - 12/28/2011
    Making a grinding nose in the transfer case
    Truck is moving and making nose
    0 answer
  • Alberto
    Alberto - 2002 Hummer H1 - Transmissions & Drivetrains - 9/20/2011
    My transmission stop working in my hummer my car is not runnin
    • Nissan Technical Advisor
      transmission could have internal problem or the the shift linkage is out of place. You have to tow the vehicle to a shop for proper diagnostic.
  • Tom
    Tom - 2007 Hummer H3 - Transmissions & Drivetrains - 8/12/2011
    Why am I hearing a clicking sound on the right side of the vehicle?
    Approx 72,000 miles. new tires. Replaced front and rear brakes and front rotors. Truck makes a groan-groan noise when in reverse after sitting all night, then going forward a click-click which quiets as speed passes 45-50 mph. Feel a slight wooble from the rear ...
    • yboy82
      8/12/2011 yboy82
      You should check the condition of your axle shaft bearing, might be dry/worn/damaged.
  • Jose
    Jose - 2003 Hummer H2 - Transmissions & Drivetrains - 8/2/2011
    Why do the speedomiter and rpm gages are not working propertly
    • HouseCallAuto
      10/31/2010 HouseCallAuto
      You have a bad instrument panel cluster. Call a local GM dealer and ask if they can "goodwill" it. use those words. Secret campaign as these clusters are dropping like flies. be nice though, they are not obligated to do anything for you. A new cluster installed would normally cost over a grand.
    • olfart
      11/20/2010 olfart
      Had my cluster rebuilt for abt $150. Check on eBay. Several guys do it. Mine works great now.
    • sergio
      8/2/2011 sergio
      I had mine repaired for $179. Gauges and lite diode. Sent unit to Minnesota and had it back in 5 days. I believe it was D & D electronics.
  • benhenshaw
    benhenshaw - 2003 Hummer H2 - Transmissions & Drivetrains - 6/28/2011
    It will not go into 4wd low or mediam the light guest flasshes then stops whays wrong
    0 answer
  • fcp
    fcp - 2006 Hummer H3 - Transmissions & Drivetrains - 3/21/2011
    What breaks if a h3 was towed in park
    drove from the tow yard then shifter dropped all the way down while trans stopped in neutral....then pushed shifter up and shifter locked in park and trans stayed in neutral
    • Bobby
      3/21/2011 Bobby
      Usually in this case possibly the parking pawl gets broken, what is also possibly it sounds like your shift linkage possibly broke or what they might have done to move the vehicle was disconnect the shift cable or linkage if that is what your vehciel uses and manually moved it into neutral to tow the truck.
  • Imongan
    Imongan - 2006 Hummer H3 - Transmissions & Drivetrains - 11/27/2010
    Why is my H3 Hummer drive for only two minutes and completely stops. I have tried all available reset buttons.
    75,000 Mile Engine runs fine Drive for 2 minutes and stops Will not drive anymore untill maybe after 2 hours for only about 2 minutes
    • HouseCallAuto
      11/27/2010 HouseCallAuto
      And you have not mentioned if any warning lights are on? Any warning messages? Any service light? You must attach a code reader and read the fault codes.
      11/27/2010 Imongan
      There is no warning light. Code reader did not show any thing. I am trying my options before replacing the transmision
  • Paul
    • don
      9/28/2010 don
      Make sure you are not holding or leaning on the gear selector . this sometimes makes the transmission think you aer trying to shift it.