Checking the gear ratio question

Woody3882

5 Year Member

Jun 19, 2018

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9

18

Bradenton Fl 34212

Jul 3, 2022

#1

• Jul 3, 2022

• #1

I am going to be replacing my 65 Mustang 289 Rear end gears but first I have to figure out the ratio that is in there.
I have read numerous articles on how to count the revolutions of the wheel compared to the drive shaft.
I have repeatedly done the process and came up with one full wheel turn equals 1.4 shaft turns.
I even did the wheel ten times and came up with 14 shaft turns. Regardless it is only 1.4 turns
What could my wheel ratio be.
Thanks.

 

2Blue2

will be trying this sex one when I can find it

Mod Dude

Mar 5, 2019

4,430

2,893

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Oahu

Jul 3, 2022

#2

• Jul 3, 2022

• #2

Assuming the following, No Axle Tag, no Door tag and thats its the stock 8 inch;


I come up with 3:00 for your numbers but I could be wrong.
Need more info.

 

KRUISR

10 Year Member

Apr 16, 2015

1,793

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Jul 3, 2022

#3

• Jul 3, 2022

• #3

If your set up is still stock, I agree with 2Blue2 - what is your axle code on door tag. Is your rear end open or posi?

Alternatively, try turning the drive shaft to get one wheel revolution.

 

Woody3882

5 Year Member

Jun 19, 2018

84

9

18

Bradenton Fl 34212

Jul 4, 2022

#4

• Jul 4, 2022

• #4

The car was in a ten year on and off restoration that I recently finished. So I do not count on the door tag to still be accurate. There is no Axle tag so I have to assume that it has been worked, that is why I want to figure it out It is not Posi. I did the turning of the drive shaft (several times) and come up with 1.4 shaft turns to one full wheel turn.
Thanks I appreciate any help.

 

Woody3882

5 Year Member

Jun 19, 2018

84

9

18

Bradenton Fl 34212

Jul 4, 2022

#5

• Jul 4, 2022

• #5

As a follow up for others in the future, Something that all of the training articles and videos fail to tell.
When rotating the wheel to count the shaft revolutions,
1) block the other wheel so it will not also turn
2) when you find the number of shaft rotations, you must double the number
to get the true ratio.
I had 10 wheel rotations with 14 shaft rotations. 14 divided by 10 equals 1.4
double the 1.4 equals 2.8 gears.
I could be wrong but now it makes sense.
Once again I was educated at the school of hard knocks, and only had to do the same project 4 times
to get the same results.
Thanks to all, I do appreciate all input
Woody3882aol.com

 

2Blue2

will be trying this sex one when I can find it

Mod Dude

Mar 5, 2019

4,430

2,893

163

Oahu

Jul 4, 2022

#6

• Jul 4, 2022

• #6

Most came with 2:80 or 3:00 so its safe bet.

 

KRUISR

10 Year Member

Apr 16, 2015

1,793

884

143

Jul 4, 2022

#7

• Jul 4, 2022

• #7

Woody3882 said:

I had 10 wheel rotations with 14 shaft rotations.

Click to expand...

Was this done with one wheel blocked?

Woody3882 said:

1) block the other wheel so it will not also turn
2) when you find the number of shaft rotations, you must double the number
to get the true ratio.

Click to expand...

This is not true for a posi.

If I remember correctly, on a non-posi, the wheel needs to be blocked because otherwise the opposite wheel will spin backwards which affects the count on the driveshaft.

 

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