85 Gt T5 Tranny Oil And 7.5 Rear Diff Oil Question

Discussion in 'Fox 5.0 Mustang Tech' started by KillaGT, Jul 22, 2013.


  1. KillaGT

    KillaGT Member

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    I don't have owner manual . What gear oil for t5 and rear diff is 7.5 with 3.73 gear swap . What gear oil do you guy recommend ?

    For 1985 mustang gt
  2. f8tlfiveo

    f8tlfiveo My wife likes my spool and blow-off valve.

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    Automatic trans fluid in the t-5..don't remember off hand which one though


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  3. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    dextron 3/Mercon in the trans. Conventional is recommended.
  4. 4cammer72

    4cammer72 Likes to drop it and leave it crusty lookin

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    that's only for world class t5 trannys, if its not it takes gear oil...you need to check the tag and reference a t5 guide to figure which tranny you have first....
  5. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    Correct. The changeover was mid 1985, so you'll need to check tags.

    If tag is missing, there are ways to externally identify, but you'd have to pull the trans to look at the front main shaft bearing race

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