5.0 driven gear w 3.27

H

habiv

Member

Oct 28, 2004

125

1

16

Mar 4, 2008

#1

• Mar 4, 2008

• #1

I am going to have the rear end gears changed in my car and I am not sure which driven gear I need. The car is a 90 GT w/ T5 transmission and I am having 3.27's put in. There are a couple of choices I have seen but I am not sure what the difference between the two is. Here are the two driven gears that I have seen.

SPEEDO "DRIVEN" NYLON GEAR RED 21 TEETH:
http://www.mustangsunlimited.com/it...in&subCategory=Speedometer+Gears&CatKey=74-01

SPEEDO "DRIVEN" NYLON GEAR PINK 19 TEETH:
http://www.mustangsunlimited.com/it...in&subcategory=Speedometer=Gears&CatKey=74-01

 

BK_CAULEY

it's built for speed not longevity, woman

Dec 26, 2006

0

10

49

Thomasville, ga

Mar 4, 2008

#2

• Mar 4, 2008

• #2

im not so sure about the last one but i know the first one should do it. i dont know why or how the 19 tooth could calibrate the same as a 21 but if it where me i would use the rd gear. but maybe someone else can better explain why they both calibrate for 3.27's

 

Fast63

New Member

Sep 20, 2007

717

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0

Mar 4, 2008

#3

• Mar 4, 2008

• #3

I think the drive gear inside the transmission is different in some T-5's. I think some are 8 tooth and some are 7 tooth. So, if yours has the 8 tooth gear in the transmission, you want the 21 tooth gear and if you have the 7 tooth, you want the 19 tooth gear. From what that one site says, your 90 GT probably has the 8 tooth transmission gear and you will need the 21 tooth speedo gear.

 

TRWXXA

Member

Jan 18, 2003

190

1

19

RIGHT BEHIND YOU!!!... Made you look.

Mar 5, 2008

#4

• Mar 5, 2008

• #4

Don't forget that your tire size has a lot to do with it too.

25.5" tires would require a 21-tooth (red) driven gear with an 8-tooth drive gear, and an 18-tooth (yellow) driven gear with a 7-tooth drive gear.

26" tires would require a 20-tooth (black) driven gear for the 8-tooth drive gear, while the 18-tooth would still be close with the 7-tooth drive gear.

 

H

habiv

Member

Oct 28, 2004

125

1

16

Mar 5, 2008

#5

• Mar 5, 2008

• #5

Fast 63 - I will also be buying the drive gear. I was going to get the one in the link below and I think I have answered my own question. At the bottom of the page it says related parts and there is a part # for the 19 tooth driven gear. So I guess I need to get the 7 tooth drive gear and the 19 tooth driven gear?

SPEEDO "DRIVE" NYLON GEAR YELLOW 7 TEETH ORIG:
http://www.mustangsunlimited.com/it...in&subCategory=Speedometer+Gears&CatKey=74-01

 

Fast63

New Member

Sep 20, 2007

717

0

0

Mar 5, 2008

#6

• Mar 5, 2008

• #6

Yes, that is right, since you are getting the 7 tooth gear in the transmission, you will match it with the 19 tooth speedometer gear to be correct for your 3.27 rearend ratio. But that is only if you have the stock tire size, because as TRWXXA mentioned, a different tire diameter will affect your setup. What size tires do you have?

 

2000xp8

SN Certified Technician

Aug 8, 2003

8,016

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NJ

Mar 5, 2008

#7

• Mar 5, 2008

• #7

Out of curiousity, why are you going to use 3.27's?
Anyone that i know that has ever had them, ditched em after a short period of time.

 

H

habiv

Member

Oct 28, 2004

125

1

16

Mar 5, 2008

#8

• Mar 5, 2008

• #8

I have pony wheels w/stock tire size so i think i am good. thanks for all of the help.

2000xp8 said:

Out of curiousity, why are you going to use 3.27's?
Anyone that i know that has ever had them, ditched em after a short period of time.

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Those people don't drive like I do