Thread: Chasing

Originally Posted by isuzurover

Great info John - Doesn't Dougal have a 5-speed isuzu box mated to an LT230 though?

Yep.
It fits, but it's tight along the side where John ran into "negative clearance". The 5 speed (MSA-5G) is quite a bit shorter than the 6speed, due to the shorter bellhousing you've got plenty of space for the relevant adaptor plates and shaft.

Shift levers are something I haven't got an elegant solution for yet.

Some ratios which I've accumulated, many provided by John.

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


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

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

While we're all yakking about gearboxes, I thought I'd mention my 4BD1 engine is still for sale It does come with a gearbox (an LT77S) and while I admit it's not a 12 speed hyperdrive mega box with a titanium casing and developed to handle 800 bhp for extreme off road racing, it will do the job!!

Originally Posted by Dougal

Yep.
It fits, but it's tight along the side where John ran into "negative clearance". The 5 speed (MSA-5G) is quite a bit shorter than the 6speed, due to the shorter bellhousing you've got plenty of space for the relevant adaptor plates and shaft.

Shift levers are something I haven't got an elegant solution for yet.

Some ratios which I've accumulated, many provided by John.

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


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

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

Great info Dougal!
What boxes were fitted to the 4BD1s though? Any info on the Aisin/Allison autos?

The gearbox in the Rodeo Jackaroo with 4JB1 had different ratios to the onw you list - low is only 3.6:1 or so. Any more info on what the box you mention was fitted to?

My 6 speed (MXA-6R), wasn't originally behind a 4BD1.

The ratios are also different to any of the others in Dougal's list. I had written them down once upon a time.

1st is close enough to 5:1. 4th is 1:1, 5th and 6th are both overdrive.

When I get a chance, I will check them out so the list can be updated.

Originally Posted by isuzurover

Great info Dougal!
What boxes were fitted to the 4BD1s though? Any info on the Aisin/Allison autos?

The gearbox in the Rodeo Jackaroo with 4JB1 had different ratios to the onw you list - low is only 3.6:1 or so. Any more info on what the box you mention was fitted to?

The MSA series of boxes were fitted to the 4BD1's and 4BE1's.
My engine came from japan with an MSA-5P attached, I have recently swapped it to an MSA-5G.
The NPR's in the US seem to have the MSA-5D box which has no overdrive.

The smaller NPR's (fitted with the 3.3L 4BC2) have the MSB boxes which are physically a lot smaller and lighter than the MSA's.

Sorry I've got nothing on the Aisin automatics.

The MXA boxes appear to be an updated MSA box, similar ratios but aluminium housing. You'll notice the MXA-5R is almost identical ratio wise to the MSA-5R.

Originally Posted by Dave_S

While we're all yakking about gearboxes, I thought I'd mention my 4BD1 engine is still for sale It does come with a gearbox (an LT77S) and while I admit it's not a 12 speed hyperdrive mega box with a titanium casing and developed to handle 800 bhp for extreme off road racing, it will do the job!!

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