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Differential Fluid Change Question.

Discussion in '1994-2004 V6 Mustang Tech' started by HumanSVD, Apr 6, 2019.

  1. HumanSVD

    HumanSVD Member

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    Going to change it out a month from now but I'm a bit confused. The Haynes Manual specifies two different fluid capacities but it doesn't specify what size goes to which version 3.8l vs 4.6l.

    Mine is a 2002 V6 3.8l. Is the capacity 3.25 pints or 3.75?

    I know it's all based on the ring gear size.

    7.5 = 3.25
    8.8 = 3.75

    Which one would I have? I misplaced my owners manual.

    Also, when changing the fluid put, do I have to remove the cover plate and change the gasket? The H manual says I can pump it out but I'm not sure if theres a specific one out there for this. It's not leaking but I don't really want to deal with the gasket mess if I don't have to. There isn't a drain plug on the cover and the aftermarket ones aren't worth the cost.

    Any thoughts?
     
  2. six gun

    six gun Active Member

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    All V6 models back then came with 7.5" so it should be the lower capacity.

    You can siphon it out from the fill plug which is on the main body, front driver side, of the differential case (it accepts the end of a 3/8 ratchet extension), but personally it's a good idea to crack off the diff cover to drain that way - that will allow more easily any metal shavings to evacuate out of there. You will need no differential additive unless you or previous owner had installed a limited slip diff. Factory one is open.
     
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  3. HumanSVD

    HumanSVD Member

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    Manual specifies to add Motorcraft Friction modifer to the total fluid amount. I think I'll just buy the gasket and change it out by removing the pan from months from now.

    Thanks!
     
  4. 08'MustangDude

    08'MustangDude Profile Violation

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    You don't need friction modifier with an OPEN differential, that is for LSDs.

    V6, you have the 7.5" rear end, open differential.
     
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  5. HumanSVD

    HumanSVD Member

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    Thanks! One less thing to buy.
     
  6. Sam36

    Sam36 Active Member

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    I usually just suck it out with an oil transfer pump (like $10) then fill it back up until it overflows out the hole.
     
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  7. 08'MustangDude

    08'MustangDude Profile Violation

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    I have a Pneumatic pump, that's what I used, then pumped
    new gear oil in till it overflowed...
     
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