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rear axle lube question..

Discussion in 'Chevy Trucks' started by spongebob, Jan 18, 2006.

  1. spongebob

    spongebob Senior Member
    Messages: 102

    im ready to change the rear axle lube on my 06 4X4 1 ton..
    dealer sold me 4qts of #89021677 synthetic lube AND 4oz. of #1052358 limited slip axle lube...
    the code of my rear axle is "G80" im told that it isnt a limited slip rear end(by the deisel guys)..the dealer gave me a read out of the G80 it says: 1976 2009 axle, rear, positraction, limited slip, positration l/slip r/axl (g80)

    anyone has any ideas..like should i use this additive?
    Last edited: Jan 18, 2006
  2. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    no additive! Like you said its not really a limited slip. the G80 is a wierd mechanical locker deal. do some searching on eaton's web site if your bored. they make our locker and have some specs for it.

    Run 75 90w synthetic(and change the front too if you have 500 or so miles on her and I'd run that up there)

    I ran mobil 1 and think its good stuff(meets the specs too) or you can run the overpriced(IMO) GM "grape" lube or anything else.
  3. ticki2

    ticki2 Senior Member
    from NH
    Messages: 175

    Yes it is a posi rear ( G80 ) . If you use dino put the additive in , if you use synthetic , no additive.
  4. spongebob

    spongebob Senior Member
    Messages: 102


    so i added 4 -32 oz bottles of synthetic and
    it didnt come out the fill hole YET..
    i can stick my little finger in there and it
    comes out wet...

    and if anyone is keeping track, i got some metal..
    or whatever (kinda pasty), on the magnet..not
    as much as i expected..truck has 1080 miles on it.
  5. calhoun

    calhoun Senior Member
    Messages: 165

    READ the manual. It is not supposed to come out the hole. I don't have the measure in front of me but the fluid level is supposed to be a certain distance below the hole. Don't over fill these.
    No additive needed.
    Why are you changing it? These are not like the old days when you needed to change the breakin oil. They come filled and good for 50K right from the factory.
  6. spongebob

    spongebob Senior Member
    Messages: 102

    Calh..the guys over at the diesel site say its the #1 thing to do..at 500 miles if towing and 1000 miles hauling..i have 1080 miles on mine and the oil was as black as.....BLACK.
  7. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    Has nothing to do with the oil/lube breaking down etc.

    It has to do with getting casting slag/sand, and all the debris from the break-in of the pinion and ring gear out of that pumpkin.

    500-2000 miles is a good range of when to do it.

    Do the front as well. I did the transfer case and transmission at the same time.
  8. sixspeed

    sixspeed Senior Member
    Messages: 306

    The pasty metal, metal shavings, etc, on the drain plug magnet is normal. It's the reason that changing the fluid after break in (like TLS said) is a very good idea.
  9. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    if you think the rear had some nasty stuff on it look on the drain plug for the front :eek:

    IT IS NOT A POSI REAR! A "posi" is chevys name they came up with in the 60's for a clutch type limited slip. It uses a clutch pack or cone. What comes in the new trucks(and trucks for MANY years) is a mechanical locker. It is a eaton peice that dosnt use a clutch pack or media to work. The reason to use the additive is becasue as its name states it is a "friction modifier". Regular lube dosnt have the right caracteristics for the clutch material in a clutch type limited slip, it needs to have a bit of it to work correctly. Some run a bit more or less modifier to suit thier tastes but that is another topic.

    The rear end isnt broke in from the factory

    Trust me;)
  10. spongebob

    spongebob Senior Member
    Messages: 102

    does the front axle work when not in 4X4?
  11. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    1/2 of it is constantly spinning. Your CV's are always spinning, all the front end parts just arnt engauged with each other.
  12. Bad Luck

    Bad Luck Senior Member
    Messages: 741

    I wish I took a pic when I finally changed my front diff fluid. It was a milky white and gray and the magnet pulled about a 1 inch slug of muck out with it. Drained it, put the GM stuff back in, ran it for about 100 miles, drained it again and re filled it. All is well now.