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might be a dumb question but. . .

Discussion in 'Chevy C/K Truck Forum' started by SGSelby, Jan 24, 2012.

  1. SGSelby

    SGSelby New Member

    I know this might be a dumb question but I cant get an answer unless I ask. My truck is a 94 k1500 z71 and I cant for the life of me figure out what rear end is in it? also I have noticed a substantial loss of power going up steep inclines and an even greater loss of fuel economy over the last month, changed the plugs, wires, cap/rotor, and injectors. thinking it might be a vacuume issue but ive been known to be wrong before. Any ideas before I start dumping money into it that I might not have to?
  2. Red Z71 Max

    Red Z71 Max Rockstar 3 Years ROTM Winner 1000 Posts

    Take it to a shop that run a diagnostic scan and see what fault codes its throwing out. Could be a number of sensors!!!
  3. mfleetwood

    mfleetwood Rockstar 4 Years ROTM Winner 5000 Posts

    To identify your rear end and/or gears, check your RPO codes in your glovebox...write them down or take a picture, as there are a lot of them. Your gear ratio will be 3 digits and should start with a G or H. The rear end itself will probably start with a G. Use the link below to find out what your code means.

    http://www.angelfire.com/ny2/96transam/rpocodes.html
  4. outalne94z71

    outalne94z71 Member

    it is most likely the 8.5 10 bolt rear, there was a optional 9.5 14 bolt, if it has 14 bolts on the cover you then have the optional 6 lug 9.5 , most z71 trucks had the 3:73 gears and a couple had the 3:42, like stated above you need to look up the rpo code for your ratio.

    GENERAL MOTORS RPO CODES:
    RPO............Ratio
    GM1............2.59:1
    GU2............2.73:1
    HC2............2.76:1
    HE3/G44.....3.07:1
    GU4............3.08:1
    GU5............3.23:1
    GU6............3.42:1
    GT4............3.73:1
    GT5/GT8.....4.10:1
    HC4............4.56:1


    losing power could be all kinds of things, could be low fuel pressure, worn timing chain, plugged cat converter or even a vacuum leak.
    Last edited: Jan 25, 2012
  5. SGSelby

    SGSelby New Member

    well I can tell you that there are ten bolts on the back side of the diff. but unfortunately the sticker inside my glovebox is so faded and worn out that all I can read is the last half of my VIN! that information wouldnt happen to be found anywhere else on the truck, would it?
  6. mfleetwood

    mfleetwood Rockstar 4 Years ROTM Winner 5000 Posts

    I'm not sure where another RPO tag location could be for your vehicle...maybe someone else can answer that. In the meantime, I think there is website in which you can enter your VIN # and it will tell you what your RPO codes are, so I'll see if I can find it.

    ---------- Post added at 07:19 PM ---------- Previous post was at 07:06 PM ----------

    While searching around, I found that some people find their RPO codes in the spare tire area, either under the lid or on the inside bottom of the compartment. Not sure where you spare tire compartment is, but that may be worth a try.

    ---------- Post added at 07:34 PM ---------- Previous post was at 07:19 PM ----------

    Sorry, the site I usually go too is shut down (compnine)....sorry.
  7. outalne94z71

    outalne94z71 Member

    vin# in your door sticker or on your dash can be taken to any dealer and they can get you your rpo codes
  8. Untouchable

    Untouchable Member 2 Years 100 Posts

    You can also go to http://www.decodethis.com/ and enter your VIN. I used it a few weeks ago and figured out a lot about my truck. I just don't remember everything it lists.
  9. SGSelby

    SGSelby New Member

    wasnt sure if you meant the spare tire tool storage compartment or my spare tire compartment but unfortunately it wasnt on the tool storage compartment and neither was any of the tools! I will just have to go to a dealer w my vin to get it. this leads me to my next question, where can i get the tool kit that i need to remove my spare tire? or what can I use to substitute those tools? I have a jack and lug wrench that I keep in my toolbox but I am not sure what to use to lower the spare, I know how to lower the spare I just dont know what the end of the rod should be that goes through the hole in my bumper and I cant seem to find any kind of replacement kit anywhere. thanks for all the help on my previous questions I am still doing some troubleshooting on my loss of power/gas mileage problem but I will let you know what I come up with as this seems to be a common problem with that year and model
  10. Coach24

    Coach24 Rockstar 3 Years 5000 Posts

    i am guessing cat converter on the decrease of power and increase of fuel consumption quick test should reveal it.
    tire tool? wrecking yard for cheap replacenment

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