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Axle/Transmission Ratio Comparison

Compare Axle Ratios, Transmission Ratios, & Drivetrain Combinations

Considering a transmission swap? Researching taller or shorter axle gear sets? Building a custom drivetrain combination? The following tool will help you calculate engine speed in revolutions per minute (RPM) based on various criteria, including axle and transmission ratios. You can then compare up to three different combinations and see how they differ. Charting drivetrain combinations is a useful exercise if you're considering swapping drivetrain products or ratios in order to visualize the overall effects that such changes will have.

Instructions: Input axle ratio, transmission ratio, tire diameter, and vehicle speed for up to three different drivetrain combinations to view engine speed (RPM) under those conditions.

 

 

Original

Variation 1

Variation 2

Axle Ratio:

: 1

: 1

: 1

Transmission Ratio*:

: 1

: 1

: 1

Tire Diameter**:

inches

inches

inches

Vehicle Speed:

mph

mph

mph

Engine Speed:

RPM

RPM

RPM

*For automatic transmissions, calculations will only be accurate under the assumption that the torque converter is locked.
**Advertised tire sizes are nominal values. For best results, measure actual tire height to nearest 1/4 inch.

 

Common Transmission Ratio Chart

Transmission

1st
(:1)

2nd
(:1)

3rd
(:1)

4th
(:1)

5th
(:1)

6th
(:1)

R
(:1)

GM TH350

2.52

1.52

1.00

-

-

-

2.07

GM TH400

2.48

1.48

1.00

-

-

-

2.07

Ford C4

2.46

1.46

1.00

-

-

-

2.18

Ford C6

2.46

1.46

1.00

-

-

-

2.18

Chrysler 727

2.45

1.45

1.00

-

-

-

2.20

Chrysler 47RE/47RH

2.45

1.45

1.00

0.69

-

-

2.21

Chrysler 48RE

2.45

1.45

1.00

0.69

-

-

2.21

Ford AOD/AODE

2.40

1.47

1.00

0.67

-

-

2.00

Ford E4OD

2.71

1.54

1.00

0.71

-

-

2.18

GM 4L60E

3.06

1.63

1.00

0.70

-

-

2.29

GM 4L80E

2.48

1.48

1.00

0.75

-

-

2.07

Ford 4R100

2.71

1.54

1.00

0.71

-

-

2.18

Chrysler 68RFE

3.23

1.84

1.41

1.00

0.82

0.63

4.44

Ford 5R110W (TorqShift 5)

3.11

2.20

1.54

1.00

0.71

-

2.88

Ford 6R140 (TorqShift 6)

3.97

2.32

1.52

1.15

0.86

0.67

3.28

Allison 1000 (5 spd)

3.09

1.81

1.41

1.00

0.71

-

4.48

Allison 1000 (6 spd)

3.09

1.81

1.41

1.00

0.71

0.61

4.48

Aisin AS69RC

3.75

2.00

1.34

1.00

0.77

0.63

3.54

Muncie SM465

6.55

3.58

1.57

1.00

-

-

6.09

Borg Warner T-19

4.02

2.41

1.41

1.00

-

-

6.96

GETRAG G360

5.53

3.02

1.60

1.00

0.77

-

5.03

New Venture NV4500 (Dodge)

5.61

3.04

1.67

1.00

0.75

-

5.61

New Venture NV4500 (late GM)

5.61

3.04

1.67

1.00

0.75

-

5.61

New Venture NV4500 (early GM)

6.34

3.44

1.71

1.00

0.73

-

6.34

New Venture NV5600

5.63

3.38

2.04

1.39

1.00

0.73

5.63

ZF S5-42, S5-47 (wide ratio)

5.72

2.94

1.61

1.00

0.76

-

5.24

ZF S6-650, S6-750

5.79

3.30

2.10

1.31

1.00

0.72

5.23

Mercedes G56 (05 - 07)

6.29

3.48

2.10

1.38

1.00

0.79

6.29

Mercedes G56 (07.5+)

5.94

3.28

1.98

1.31

1.00

0.74

5.42

 

For more information on transmissions found in diesel applications, see transmission tech @ Diesel Hub.