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85 Gt T5 Tranny Oil And 7.5 Rear Diff Oil Question

  • Thread starter Thread starter Killa
  • Start date Start date Jul 22, 2013

Killa

Active Member
Jul 9, 2007
1,006
56
49
Jul 22, 2013
#1
  • Jul 22, 2013
  • #1
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
 

f8tlfiveo

My wife likes my spool and blow-off valve.
Aug 8, 2007
1,585
102
64
Lancaster, PA
Jul 22, 2013
#2
  • Jul 22, 2013
  • #2
Automatic trans fluid in the t-5..don't remember off hand which one though
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,265
17,952
224
Massachusetts
Jul 22, 2013
#3
  • Jul 22, 2013
  • #3
dextron 3/Mercon in the trans. Conventional is recommended.
 

4cammer72

Likes to drop it and leave it crusty lookin
Mar 28, 2007
90
6
9
west columbia south carolina
Jul 24, 2013
#4
  • Jul 24, 2013
  • #4
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....
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,265
17,952
224
Massachusetts
Jul 24, 2013
#5
  • Jul 24, 2013
  • #5
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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