Differential Refill

Discussion in 'General Turbo Buick Tech' started by jemook, Apr 20, 2017.

  1. jemook

    jemook
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    Hi Folks,
    Does anyone here know how many pints of gear oil are needed to refill the diff. to the correct level with the TA Perf. aluminum cover? Also, has anyone used the Lucas heavy duty high performance 80W-90 dino gear oil? I generally use Valvoline, but came across the Lucas oil today for a good price. Says you don't have to use limited slip additive, but I got a bottle of GM additive anyway. Thanks for any info.
    John
     
  2. SS/GN

    SS/GN
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    It all works fine. I like the synthetic stuff penzoil and Lucas are both good choices. To be honest I don't know if there is any real diff between the 75w90 and the 80w90
     
  3. earlbrown

    earlbrown
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    All things being equal, they'll both be 90 at operating temp. So, yeah, no real difference.


    I'd make sure the clutch pack chatters before pouring in the additive.
     
  4. michael evans

    michael evans
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    O'Ralley's said stock was 1.8 quarts stock, but I but in two-one quart-bottles and posi anti-rattle and had room to add in a little more.
     
  5. earlbrown

    earlbrown
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    So are you pointing out that parts stores don't know dick, or that parts stores don't know dick?
     
  6. gusszgs

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  7. 1KWIKSIX

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    I just finished refilling mine and I was able to empty the oil removed in a drain pan which filled a 2 quart empty cardboard milk box.
    My rear end has the GNX aluminum differential cover which is a bit deeper than the stock tin cover but should be close to the TA cover.

    Bought & installed 2 US Quarts of Coastal 80W-90 (GL5) oil from AutoZone + added a 6oz bottle of Auburn Posi Lube. Auburn states to add 3oz per quart of their rear end oil.
    Note: The GM Posi Lube (3 oz bottle) states just add the one bottle to the filled differential.

    A note from the factory service manual states to add enough oil to be about 1" below the oil fill hole.
    You'll need to get your little pinky wet in order to be able to determine this.
     
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  8. SS/GN

    SS/GN
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    As all of my colleagues have said 2 quarts is the magic number. You need room for it to expand! Do yourself a favour and put a magnetic oil fill plug in it:cool:
     
  9. dynoman

    dynoman
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    That is what I used in in my stock posi rear with NO additive and no chatter . If it does chatter then add just enough additive to stop it .
     
  10. jemook

    jemook
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    Thanks so much for the info. Appreciate everyone's input. I'll be getting the car out next week for a show on the 6th. By the way, one my former working buddies has a 2016 Challenger 5.7 Scat Pack that he wants to run against my GN. He believes that he will clean my clock. I don't think he will be any problem. Everyone have fun this summer.
    John
     
  11. Boostrules

    Boostrules
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    Let us know how your run against him turns out. Enjoy the show.
     

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