Thread: Isuzu gearbox info.

This do the trick?
http://www.aulro.com/afvb/isuzu-land...tml#post738604

From here -
http://www.aulro.com/afvb/good-oil/5...verdrives.html

My Isuzu gearbox is a MXA-6R. 5th and 6th are both O.D.
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

The later MBP-6P gearbox from Isuzu NQR 450 has the following ratios:
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

Originally Posted by Bush65

My Isuzu gearbox is a MXA-6R. 5th and 6th are both O.D.
...

The later MBP-6P gearbox from Isuzu NQR 450 has the following ratios:
....

Thanks John - I am assuming these are for the 4BD1.

I am currently interested in gearboxes to mate the 6BB1 (8 tonner) but the ratios sound good.

We'll have to discuss my 110 F/C project and mating the Isuzu boxes to the LT230.

Originally Posted by Lotz-A-Landies

Thanks John - I am assuming these are for the 4BD1.

I am currently interested in gearboxes to mate the 6BB1 (8 tonner) but the ratios sound good.

We'll have to discuss my 110 F/C project and mating the Isuzu boxes to the LT230.

Neither of the boxes above were ever fitted to a 4BD1. I have never seen a 4BD1 which came from the factory with a 6 speed. However all the B engines share the same bolt pattern.

John has mentioned a few times that the front output of an LT230 would foul on the MXA-6R. So your only option would be to run a divorced case like this:

Originally Posted by Lotz-A-Landies

Thanks John - I am assuming these are for the 4BD1.

I am currently interested in gearboxes to mate the 6BB1 (8 tonner) but the ratios sound good.

We'll have to discuss my 110 F/C project and mating the Isuzu boxes to the LT230.

Not originally for a 4BD1.

I don't know for sure what engine my MXA-6R was on originally. I had to modify another Isuzu bellhousing to mate it to my 4BD1-T, which is from an Isuzu truck - not Land Rover.

I have an Isuzu workshop manual, that has the MXA-6R gearbox in it. If I dug it up it will tell me an engine (one of the 4H family I think, but not definite) and truck that it was used in - if you need this information let me know and I will look for it.

The modification involved some relatively simple machining at the gearbox end to suit the greater centre distance between the input and lay shafts - in Isuzu gearboxes, the bearings protrude a small amount to act as location of the bellhousing.

My gearbox looks like it was developed from a 5 speed box and 6th gear is in an extension housing on the rear. I think that might explain why 5th and 6th are both overdrive. AFAIK in all later 6 speeds, 5th is 1:1 and only 6th is O.D. (but 1st is lower than mine).

The information that I posted for the MBP-6P came from NQR 450 specifications that listed the engine as a 4HE1-XS. It is possible that it may be used in other trucks and with other engines.

John - I am not sure if you have posted this before, but have you measured the weight and length of your box (ideally compared to an LT95)?

Originally Posted by isuzurover

John - I am not sure if you have posted this before, but have you measured the weight and length of your box (ideally compared to an LT95)?

Have not measured the weight. Because the casing is cast iron and internals are more robust than an LT95, it has considerable mass.

I no longer have any complete LT95's to compare to.

The Isuzu bellhousing is cast aluminium, and because it is short, the overall length of the gearbox plus bellhousing is similar to an R380.

From bellhousing to face where the handbrake bolts on, is about 15 mm less than from the bellhousing of an R380 to mounting face for LT230.

I have removed the handbrake and modified the output shaft and if my transfer case adapter is included, it is about 15 mm longer than a R380.

All lengths were taken from mounting face to mounting face and not including any shaft protrusion.


Edit: I have lifted the gearbox into and out of the back of my disco (and I'm no weight lifter!). I doubt I could do that with an LT95, partly because they are so awkward and partly because of additional weight of the t/case (but LT95's have faded from my memory now).

Apologies for the hi-jack Diana.

Have a look through www.4btswaps.com - Dougal is a moderator and may have some ideas for a search. That site covers various diesels and may have a link somewhere for the 6 cylinder Isuzus....

As for the 4BD1 / M series gearboxes....

Here's a MSA? i think behind a truck 4bd1. The adaptor plate for the LT-230 is a 40mm alloy plate which, when clearing the sump/diff and steering box, puts the TC mounts in the same spot as the LT-77 did. Bearing in mind that the intermediate casing is a different length for the LT-77 as the R380.

When I bought the box it had a 100kg shipping weight - I assume this included the crappy wooden box it came in - anyway, I've lifted it in and out of the Disco a time or two and I'm no Hurcules either - maybe 60kg's ???

Matt.