23. Gear Ratios

Table 23-1 contains the RPOs, gear ratios, years offered, and applications for the 1983-1992 GM F body T5s. I found little information on the ML8 T5, but it appears to be the same as the MK5.

As a set, 5th gear is interchangeable with other T5s, but only within the World Class or nonWorld Class design. To maximize the overdrive in a World Class V8 T5 (MK6 or M39), the 5th gear set from an MB1 World Class T5 could be installed to obtain a 5th gear of 0.56:1. To maximize the overdrive in a nonWorld Class V8 T5 (MK6 or M39), the 5th gear set from an ML3 nonWorld Class T5 could be installed to obtain a 5th gear of 0.53:1. To minimize the reduction in rpm from 4th to 5th gear in either a World Class or nonWorld Class V8 T5, the 5th gear set from the MK6 T5 is the best choice at 0.73:1.

Table 23-1: 1983-1992 GM F Body T5 RPOs, Gear Ratios, and Years Offered

 

1st Main

2nd Main

3rd Main

4th Main

5th Main

 

 

RPO

1st Cluster

2nd Cluster

3rd Cluster

4th Cluster

5th Cluster

Engine

Years Offered

MK6

32.00

33.00

30.00

24.00

31.00

V8

1983-1984; 1988-1991

 

14.00

22.00

29.00

31.00

55.00

 

 

ratios

2.95

1.94

1.34

1.00

0.73

 

 

M39

32.00

33.00

30.00

24.00

25.00

V8

1985-1991

 

14.00

22.00

29.00

31.00

51.00

 

 

ratios

2.95

1.94

1.34

1.00

0.63

 

 

MK4 (1st design)

33.00

31.00

29.00

22.00

27.00

L4

1983

 

15.00

23.00

34.00

35.00

59.00

 

 

ratios

3.50

2.14

1.36

1.00

0.73

 

 

MK4 (2nd design)

33.00

31.00

27.00

22.00

27.00

L4

1983-1984

 

15.00

23.00

31.00

35.00

59.00

 

 

ratios

3.50

2.14

1.39

1.00

0.73

 

 

MK5 (1st design)

33.00

31.00

29.00

22.00

25.00

L4; V6

1983

 

15.00

23.00

34.00

35.00

51.00

 

 

ratios

3.50

2.14

1.36

1.00

0.78

 

 

MK5 (2nd design)

33.00

31.00

27.00

22.00

25.00

L4; V6

1983-1984

 

15.00

23.00

31.00

35.00

51.00

 

 

ratios

3.50

2.14

1.39

1.00

0.78

 

 

ML8

33.00

31.00

27.00

22.00

25.00

 

 1984

 

15.00

23.00

31.00

35.00

51.00

 

 

ratios

3.50

2.14

1.39

1.00

0.78

 

 

ML3

32.00

31.00

25.00

21.00

25.00

L4

1985-1986

 

15.00

25.00

31.00

37.00

61.00

 

 

ratios

3.76

2.18

1.42

1.00

0.72

 

 

MB1

32.00

31.00

27.00

21.00

23.00

V6

1985-1991

 

14.00

23.00

32.00

37.00

53.00

 

 

ratios

4.03

2.37

1.49

1.00

0.76

 

 

 


Originally Released 18 June 2003

updated 27 August 2007