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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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2.73 to 3.73 gears (any problems?)

  • Thread starter Thread starter green
  • Start date Start date May 12, 2007
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green

New Member
Apr 26, 2003
291
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0
May 12, 2007
#1
  • May 12, 2007
  • #1
hey, hows it going, i have a mustang with a set of 2.73 gears, and now i want to put in 3.73 gears. but a couple of people told me that when you step up from a 2 to a 3 that there will be problems, but if you go to a say 3.08 to 3.73 that there is no problems at all, because your staying in the 3,s. if this is true, what do i need when going from 2.73 to 3.73? alot of shimms? etc? thank you.
 
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BaXTeR3221

Member
Jan 12, 2004
917
0
16
Orange County, NY
May 12, 2007
#2
  • May 12, 2007
  • #2
No problem with that swap. You could go to 4.10's and not have any mechanical problems. Go for it, it'll make a huge difference.
 
C

caduck

New Member
Sep 17, 2006
23
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Springfield, Or
May 12, 2007
#3
  • May 12, 2007
  • #3
No problems and makes the car alot more fun to drive and gas milage stays about the same if you can keep your foot out of it but you will find it is hard to do you will just need to change the speedo gear. Its a must mod..
 

green

New Member
Apr 26, 2003
291
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May 12, 2007
#4
  • May 12, 2007
  • #4
so the sizes of the 2.73 ring gear is the exact same size if the 3.73. i just heard someone say that when u move from a 2.73 gear to a 3.73 gear (or even a 3.08 gear) (if you step up from 2 to 3 you need some extra things to make it work. thanks
 

Shakerhood

20+ Year Stangneter
Oct 28, 2004
3,357
209
114
Ohio
May 12, 2007
#5
  • May 12, 2007
  • #5
You may pick up a Vibration after the gear swap, but a Ford Racing Aluminum Driveshaft will cure it right up.
 

whtpny

New Member
Dec 8, 2002
338
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0
Spokane WA.
May 13, 2007
#6
  • May 13, 2007
  • #6
When you buy a gear kit it will have the shims in it to set it up.
 

Aryan15

Member
Sep 22, 2003
236
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17
CA
May 13, 2007
#7
  • May 13, 2007
  • #7
I didn't have to change the pinion shim at all and I went from 2.73-3.73 but I replaced the shim anyways with the bearing swap. But I did have to swap from the carrier shims that were in the car to get the right backlash. The ford gears are awesome in that way.
 
C

Chris00GT

Founding Member
Jan 28, 2001
275
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16
York Springs, PA
May 13, 2007
#8
  • May 13, 2007
  • #8
I'm running 3.73's in my 91 and really wish I would have went with 4.10's like I have in my 00GT. Just make sure you have somebody who know's how to set up rear ends and you'll have no problems.
 

BigDanTheMan

Member
Aug 16, 2005
63
1
6
San Francisco, CA
May 13, 2007
#9
  • May 13, 2007
  • #9
you'll have to teach yourself how to shift again - that will be the only problem
 

Foxfan88

My Grandpa has great wood.
Sep 13, 2004
2,487
4
0
Miami, Ok
May 13, 2007
#10
  • May 13, 2007
  • #10
green said:
so the sizes of the 2.73 ring gear is the exact same size if the 3.73. i just heard someone say that when u move from a 2.73 gear to a 3.73 gear (or even a 3.08 gear) (if you step up from 2 to 3 you need some extra things to make it work. thanks
Click to expand...


the gear set are the same dimensions the only differences are the number of teeth on the pinion and the ring gear.
 

jtfairlane

New Member
Mar 5, 2006
468
3
0
May 13, 2007
#11
  • May 13, 2007
  • #11
green said:
so the sizes of the 2.73 ring gear is the exact same size if the 3.73. i just heard someone say that when u move from a 2.73 gear to a 3.73 gear (or even a 3.08 gear) (if you step up from 2 to 3 you need some extra things to make it work. thanks
Click to expand...

Whoever told you that, would be a person I would ignore from now on if they give you ANY car advice. The numbers are just indicating the ratio, ie. 2.73:1 or 3.73:1, and have nothing to do with the physical size of the ring or pinion. The teeth count change to change the ratio, but the ring and pinion have the same dimensions.
 

thumper460

Founding Member
Jul 24, 2000
3,022
2
56
Orange Park , Fl
May 13, 2007
#12
  • May 13, 2007
  • #12
Rocking.. you'll love it!!

All the 8.8's are mfg to the correct ping and pinion size to bolt right in!! CHEVY and OLDS and a few others need a shim and spacer and alot of other junk!! but the FORD system is pretty straight forward!! Re use the shim and spacers, as they are set to the HOUSING.. and 99% of the time they just fit perfect!! Noise?? I use the Richmond, have done Max Torq, motorsport.. they all are fine!!

Just me..............................

Thumper
 

Bad92GT

The 5 Minute Plan Man
Jun 10, 2004
492
0
0
SC
May 13, 2007
#13
  • May 13, 2007
  • #13
i threw in a set of ford OEM gears (out of an explorer i think) in the original rear end of the 92.. didnt make really any noise, no problems what so ever.. i swapped it out for another rear end i had with 3.73s and FMS posi unit.. which that makes more noise then the one i did, which was just changing gears, left the shims alone
 

TRWXXA

Member
Jan 18, 2003
190
1
19
RIGHT BEHIND YOU!!!... Made you look.
May 13, 2007
#14
  • May 13, 2007
  • #14
Only if you go to 4.56 gears or higher do you need to make any additional changes. And that would be the replacement of the standard carrier cross pin with a notched cross pin.
 
B

black5.0lx

New Member
May 10, 2007
23
2
3
Rincon, GA
May 14, 2007
#15
  • May 14, 2007
  • #15
You might have gotten that info from a Chevy guy. They require a different carrier when swapping from a 3 series to a 4 and probably from a 2 to a 3 as well. Just my 2 cents.
 
8

86bluecobra

Advanced Member
Dec 20, 2004
4,265
12
69
B.C. Canada
May 15, 2007
#16
  • May 15, 2007
  • #16
Whoever is feeding you info is not correct. You can swap without any issues. Well there will be one issue and thats how much more fun your car will be but I bet you will be able to deal with that.
 
D

Deleted member 87397

May 15, 2007
#17
  • May 15, 2007
  • #17
Main problem = buying rear tires more often
 
D

DRock9

New Member
Aug 22, 2006
359
0
0
May 15, 2007
#18
  • May 15, 2007
  • #18
So if I am swapping my stock 2.73 to 3.73 there should be no need for any ajustments? I should just just be able to take off the old ring/pinion and then swap in the new one?

Someone said you had to ajust something else and you needed special tools or something but now I am beginning to wonder whether or not I could do it myself.
 

Waz900

Member
Apr 22, 2005
41
4
18
Sewell, New Jersey
May 15, 2007
#19
  • May 15, 2007
  • #19
I paid to go from 2:73 to 3:73 in my automatic. It cost me like $575 with the speedo gear installed. The only thing that I don't like is the rear kinds whines a little bit, but if you accellerate at all it will go away.
 

thumper460

Founding Member
Jul 24, 2000
3,022
2
56
Orange Park , Fl
May 15, 2007
#20
  • May 15, 2007
  • #20
Yes... straight out swap!! USING the shims and spacers that are in there ! Just do it like we said!! IF there is NO Noise NOW>>> there wont be noise when you are done!!

Just me...................................

Thumper
 
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