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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Stock Rear End?

  • Thread starter Thread starter dcurtis
  • Start date Start date Mar 13, 2007

dcurtis

10 Year Member
Jan 19, 2006
688
7
39
Mar 13, 2007
#1
  • Mar 13, 2007
  • #1
I got my mustang yesterday and was wondering what type of differential is in it, it is a 91 Gt with the auto tranny, I think the gears are 2.73 but is it limited slip or an open diff????
 

mustanghrspower

Founding Member
Feb 27, 2001
554
0
0
Las Vegas, NV
Mar 13, 2007
#2
  • Mar 13, 2007
  • #2
Does the rear end have an ID tag on one of the cover bolts? This tag will have the gear ratio and an L if it is a locker. I have yet to see a Mustang that came from the factory with a 5.0 from 86 on that doesn't have a locker though. Sometimes they're so worn out you might think it is an open rear though.
 

SVT32VDOHC

waiting for the next hack atta
Founding Member
Nov 22, 2001
3,501
28
119
Motor City
Mar 13, 2007
#3
  • Mar 13, 2007
  • #3
mustanghrspower said:
Does the rear end have an ID tag on one of the cover bolts? This tag will have the gear ratio and an L if it is a locker. I have yet to see a Mustang that came from the factory with a 5.0 from 86 on that doesn't have a locker though. Sometimes they're so worn out you might think it is an open rear though.
Click to expand...

+1. Some diffs are already burnt up and they are only a one legged warrior. Check the tag...like stated above.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Mar 13, 2007
#4
  • Mar 13, 2007
  • #4
+2. All aero GT's had Trac Lok.
 

4G-KDMP

10 Year Member
Jul 23, 2005
935
19
39
CA
Mar 13, 2007
#5
  • Mar 13, 2007
  • #5
HISSIN50 said:
+2. All aero GT's had Trac Lok.
Click to expand...

x2
 

f4fntm

New Member
Oct 10, 2004
88
2
0
Olympia, WA
Mar 14, 2007
#6
  • Mar 14, 2007
  • #6
I'm gonna take it one step further and say: Fox GTs in all years came standard w/a Traction-Lok rear, except in 1982. That includes the '83-'84 Turbo GTs.

1991 gearing is either 2.73 or the optional 3.27.

All this per the Mustang 5.0 Technical Reference & Performance Handbook.
 

dcurtis

10 Year Member
Jan 19, 2006
688
7
39
Mar 14, 2007
#7
  • Mar 14, 2007
  • #7
It does have a tag on it but there is no 'L' on it, I'm not positive but it doesn't look like the factory unit though, I will just have to pull the cover I guess, Is there any way to make it work again if it does have the locker in it, if it doesn't does anyone know a good place to get one for a descent price, I will probably go ahead and pick up some new gears while I'm at it, either some 3.42's or 3.73's, anyway thanks for the help.
 

f4fntm

New Member
Oct 10, 2004
88
2
0
Olympia, WA
Mar 16, 2007
#8
  • Mar 16, 2007
  • #8
Take it to a diff shop and have it rebuilt. Specify that it's for a performance application and ask what they can do to make it a bit stouter.
 
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