Some gearboxes and ratios used with Isuzu 4cyl B series motors. To my knowledge all are cable change.
MSA series has existed since at least 1985, it is the heavier duty gearbox to be fitted to the 4BE1 and 4BD1 engines. Case and bellhousings are steel. Gear access is through the top aluminium cover.
MXA series appears to be the modern replacement for the MSA boxes, housings are lighter aluminium, they bolt up to the newer Isuzu 4cyl engines but can be made to fit a 4BD1.
MSB series gearboxes are lighter duty, used on th 4BC2 (3.3L) and 4JB1T (2.8 turbo) engines. Significantly more compact, gear access is through a side panel.
Other gearboxes and their ratios are included for interest.
MSA-5D
1st - 5.670
2nd - 3.415
3rd - 1.900
4th - 1.331
5th - 1.000
R - 5.680
MSA-5G,
5.788:1
2.998:1
1.594:1
1.000:1
0.776:1
5.798:1
MSA-5P,
5.788:1
2.998:1
1.735:1
1.000:1
0.776:1
5.798:1
MSA-5R,
4.987:1
2.998:1
1.594:1
1.000:1
0.728:1
4.774:1
MXA-5R
4.987:1
2.870:1
1.594:1
1.000:1
0.728:1
Isuzu MBP-6P
1st 6.378:1
2nd 3.627:1
3rd 2.239:1
4th 1.452:1
5th 1.000:1
6th 0.787:1
rev 6.595:1
MYY-6P
5.979:1
3.434:1
1.862:1
1.297:1
1.000:1
0.774:1
5.701:1
MYY-5P
5.315:1
3.053:1
1.655:1
1.000:1
0.721:1
5.068:1
Isuzu Mzz-6U
1st- 6.369
2nd- 3.767
3rd- 2.234
4th- 1.442
5th- 1.000
6th- 0.782
rev- 6.369
The mbp-6p is:
1st 6.378:1
2nd 3.627:1
3rd 2.239:1
4th 1.452:1
5th 1.000:1
6th 0.787:1
Model MSB-5S
Specification Matching Engine: 4JB1
Ratio:
1: 5.016
2: 2.672
3: 1.585
4: 1.000
5: 0.770
Rev: 4.783
Central Distance: 88
Torque: 230Nm
4JB1 fitted with MSB-5S
4BE1T fitted with MSB-5M
4BC2 fitted with MSB-5S (truck at home)
4HF1 fitted with MSA-5R (wymer brothers)
NHR (poss 4JB1) with MSC-5
MSA-5D and MXA-5D appear functionally identical
MSA series has existed since at least 1985, it is the heavier duty gearbox to be fitted to the 4BE1 and 4BD1 engines. Case and bellhousings are steel. Gear access is through the top aluminium cover.
MXA series appears to be the modern replacement for the MSA boxes, housings are lighter aluminium, they bolt up to the newer Isuzu 4cyl engines but can be made to fit a 4BD1.
MSB series gearboxes are lighter duty, used on th 4BC2 (3.3L) and 4JB1T (2.8 turbo) engines. Significantly more compact, gear access is through a side panel.
Other gearboxes and their ratios are included for interest.
MSA-5D
1st - 5.670
2nd - 3.415
3rd - 1.900
4th - 1.331
5th - 1.000
R - 5.680
MSA-5G,
5.788:1
2.998:1
1.594:1
1.000:1
0.776:1
5.798:1
MSA-5P,
5.788:1
2.998:1
1.735:1
1.000:1
0.776:1
5.798:1
MSA-5R,
4.987:1
2.998:1
1.594:1
1.000:1
0.728:1
4.774:1
MXA-5R
4.987:1
2.870:1
1.594:1
1.000:1
0.728:1
Isuzu MBP-6P
1st 6.378:1
2nd 3.627:1
3rd 2.239:1
4th 1.452:1
5th 1.000:1
6th 0.787:1
rev 6.595:1
MYY-6P
5.979:1
3.434:1
1.862:1
1.297:1
1.000:1
0.774:1
5.701:1
MYY-5P
5.315:1
3.053:1
1.655:1
1.000:1
0.721:1
5.068:1
Isuzu Mzz-6U
1st- 6.369
2nd- 3.767
3rd- 2.234
4th- 1.442
5th- 1.000
6th- 0.782
rev- 6.369
The mbp-6p is:
1st 6.378:1
2nd 3.627:1
3rd 2.239:1
4th 1.452:1
5th 1.000:1
6th 0.787:1
Model MSB-5S
Specification Matching Engine: 4JB1
Ratio:
1: 5.016
2: 2.672
3: 1.585
4: 1.000
5: 0.770
Rev: 4.783
Central Distance: 88
Torque: 230Nm
4JB1 fitted with MSB-5S
4BE1T fitted with MSB-5M
4BC2 fitted with MSB-5S (truck at home)
4HF1 fitted with MSA-5R (wymer brothers)
NHR (poss 4JB1) with MSC-5
MSA-5D and MXA-5D appear functionally identical