Thread: Isuzu gearbox ratios

Here is a list of the ratios Dougal posted on 4BTswaps a while back that I had saved


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

The 5G would be the best option in a 110 tho the 5P which I have here may well be a better option in a truck or 101 or for hauling loads

I have designed my own adaptor to fit the LT230 to the MSA I just need to pull my finger out and get the parts cut to see how it goes

As for making the spud shaft I have that sorted as well as a shifter

Had to take a pic as the info was password protected The bellhousing would need to be changed

AM

This list could do with some editing:

For strength:
MSB = 88mm gear centres (weakest box) and was fitted to 4BC2 and 4JB1T engines.
MSA = 97mm gear centres fitted to most B series Isuzu's.
MXA = 100mm gear centres (strongest box) fitted to most H series Isuzus but also 4BD2T.

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

MSA5G,
5.788:1
2.998:1
1.594:1
1.000:1
0.776:1
5.798:1

MSA5P,
5.788:1
2.998:1
1.735:1
1.000:1
0.776:1
5.798:1

MSA5R,
4.987:1
2.998:1
1.594:1
1.000:1
0.728:1
4.774:1

MXA5R
4.987:1
2.870:1
1.594:1
1.000:1
0.728:1
4.774:1

MXA-6R (I don't know year).
1st 4.987:1
2nd 2.870:1
3rd 1.684:1
4th 1.000:1
5th 0.728:1
6th 0.626:1
rev 4.774:1

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-6S
5.979:1
3.434:1
1.862:1
1.297:1
1.000:1
0.75:1
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

Model MSB-5S
Description The transmission is one horizontal manual transmission, which is manufactured in strict with Japanese ISUZU standard. It can be used on light-duty truck,minibus etc.
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: 230


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

MBG-6T fitted to 6HE1 1992 FRR32
MBP-6P fitted to 4HE1TC 1998 NPR70P
MXA-6R fitted to 4BD2TC 1994 NPR65
MXA-6R fitted to 4HG1 1996 NPR71
MLD-6A fitted to 6BD1 FRT12
MBG-6P fitted to 6BD1 1987 FSR11
MBG-6P fitted to 6HE1 1995 FSR32
MYY6 no truck listed.
MBG-6U fitted to 6HE1 1994 FRR32K
6 speed fitted to 4HE1T 1998 NPR70
MXA-6R fitted to 4HG1 NPR71P
MBG-6P fitted to 6BD1 1989 FSR11HG

Originally Posted by Ancient Mariner

Had to take a pic as the info was password protected The bellhousing would need to be changed

AM

MXA-6S A six speed double overdrive! What is it out of?

Originally Posted by Lotz-A-Landies

MXA-6S A six speed double overdrive! What is it out of?

As far as I can determine N series about 2000 The 4x4 has a cast iron bell housing instead of aluminium and use MXA 5R boxes


AM

Originally Posted by Dougal

<snip> ...
MYY6 no truck listed.
... <snip>

You will find that the MYY are in the current MY14 range.
Isuzu N Series | Light duty truck - Isuzu Australia

MYY-6S (& AMT): (4500-7500GVM/8000-11000GCM)
1st 5.979 2nd 3.434 3rd 1.862 4th 1.297 5th 1.000 6th 0.750 Rev 5.701

1. NNR 200
2. NPR-250
3. NPR-275
4. NPR-300
5. NPR-400

MZZ-6F (& AMT): (8700GVM/12200GCM)
1st 6.369 2nd 3.767 3rd 1.966 4th 1.355 5th 1.000 6th 0.782 Rev 6.369

1. NQR-450

MYY-5S (4500GVM/7000GCM)
1st 5.979 2nd 3.434 3rd 1.752 4th 1.000 5th 0.795 Rev 5.701

1. NLS-200 AWD

MYY-5T: (4500-5500GVM/7000-8000GCM)
1st 5.315 2nd 3.053 3rd 1.655 4th 1.000 5th 0.721 Rev 5.068

1. NLR-200
2. NLR-275
3. NPS-250 4X4
4. NPS-300 4X4

AMT suffix means: Automated Manual Transmission (AMT) with both fully automatic
and clutchless manual operation modes.

Hello everyone,

I am new here and will appreciate any help.

I just brought back a 6x6 110 Perentie from Sydney that I've bought from Graysonline.
Seams a good truck except the 4 speeds gear box .
Too much difference between 3rd and 4th and definitly need at least one more gear.

Lotz-A-Landies , do you know if the gear boxes that you mention would fit in my truck ?
And a 6 speed double over-drive would be even better I reckon.

Thanks

Originally Posted by Rand Lover

Hello everyone,

I am new here and will appreciate any help.

I just brought back a 6x6 110 Perentie from Sydney that I've bought from Graysonline.
Seams a good truck except the 4 speeds gear box .
Too much difference between 3rd and 4th and definitly need at least one more gear.

Lotz-A-Landies , do you know if the gear boxes that you mention would fit in my truck ?
And a 6 speed double over-drive would be even better I reckon.

Thanks

The problem you have is the lt95 gearbox/t-case you have has a single casing. You need the t-case to drive the rearmost axle.

There are people who have cut the casing in half to use the t-case only. So yes, you can fit the boxes mentioned, however there will be some custom work to mate it with the t-case part of your lt95.

To fit the box you will also need to fit a truck bellhousing to the back of the engine and sort a custom shifter mechanism.