Thread: Isuzu MSA Gearbox to LT230

well fitted ther gearbox today. Need to make some adjustments to the shifter to shorten the throw due to having a body lift and shifter hitting hi/lo lever when in low range, know big deal really just some fine tuning, should be relatively easy. Will see if i can bring the gates closer together as well, that might be a little trickier though

Some good and bads news.....

Bad news = I am back from Asia and my trip is over

Good news = There is a 12V Starter off a 4BA1 motor that bolts up to the 4BD1 and clears the landrover chassis. Boof Ed has one running on his rig.

StarterMotor.jpg


The 24V with 9 teeth - 35mm Gear OD is what I have been using.

The 12V has 9 teeth at 32mm. I have rolled the 32mm gear around the flywheel of a 4BD1 and it seems to engage fine. Seems to be the same pitch just with 1.5mm less engagement depth. As I was in a rush to head o/s I had no time to test it. So seeing I had a dead 24V starter with the 35mm gear laying around - I swapped the 35mm gear onto the 12V starter and sent it up to Boof Ed.


Good news = is now easier to do the conversion keeping 12V

Originally Posted by the_grubb

Good news = There is a 12V Starter off a 4BA1 motor that bolts up to the 4BD1 and clears the landrover chassis. Boof Ed has one running on his rig.

Isn't this the same starter I'm using? I don't know the exact origin of mine, but I've seen it on early 4BC2 12v engines also.

I run mine on 24v.

Originally Posted by Dougal

Isn't this the same starter I'm using? I don't know the exact origin of mine, but I've seen it on early 4BC2 12v engines also.

I run mine on 24v.

I have no idea if its the same as yours

I thought yours was the buldgy out reduction 2 bolt type? And thats why you had to notch your chassis?

There are three types of the 2 bolt direct drive as shown in the attachment of my last post.

12V 2.2Kw 9 teeth 32mm gear OD
24V 3.5Kw 9 t 32mm
24V 3.5Kw 9 t 35mm

Originally Posted by the_grubb

I have no idea if its the same as yours

I thought yours was the buldgy out reduction 2 bolt type? And thats why you had to notch your chassis?

There are three types of the 2 bolt direct drive as shown in the attachment of my last post.

12V 2.2Kw 9 teeth 32mm gear OD
24V 3.5Kw 9 t 32mm
24V 3.5Kw 9 t 35mm

There's no bulge or gear reduction on mine, the one on the left of your picture is it's twin. It's the solenoid hanging out that required a small notch of the chassis corner. My engine sits lower than most here as there is no body lift.
The 12v 2.2kw would be the one. My vehicle has been 24v since it was converted around 1992, it used to start in warm weather on 12v, but since the last engine rebuild (about 6 years ago) the compression is too high and it needs both batteries. I think a 12v 3.5kw starter would be good, but the 2.2kw isn't enough for me.

It pulls between high 300 and low 500 amps when cranking. Which fits quite well with a 12v starter given twice the volts. One day I'd like to replace it with a 24v version, but it's way down the list.

Yep, thats sounds about right, The soleniod sits roughly 20mm (enough for fingers to squeeze past) above the chassis on a factory built Isuzu, something to consider for anyone doing a conversion.

hey guys
i have been looking at a gearbox change soon as my lt85 in my county is starting to whine (400k without rebuild and now a turboed isuzu in front ) the whine is mainly on free run (coasting along just with a tad accelerator) and mainly in 4th.
As most will know they are a terrible gearbox but this one has served well in my opinion.
so i started looking back into the isuzu gearboxes once again but i have a few options going around which i need some external input

first one was a 5spd Nissan patrol GQ gearbox

2nd idea was the MSA-5g etc etc (needing to see what the final price was for the adaptions that grubb and others have designed)

3rd was the MXA (like bush65)

but the most recent was an idea that poped to mind and that is a MYY-5T isuzu gearbox/transfer it is out of a NPS250,300 4wd truck ...first i know that the lt230 is a strong transfer but if i was to find a MYY-5T box/transfer it would be a whole unit so no intricate or high stress parts would need to be made such as hardened and ground splined drive shafts etc etc and there would be no mixing and matching but there would still be the modifiying to fit the box of course....i then looked at the ratios and the ratios seem much better and more useable than the lt85 but im sure there would be a big problem or something i am missing/leaving out the ratios are as follows
lt85
1st=3.65:1
2nd=2.18:1
3rd=1.436:1
4th=1:1
5th=0.8:1

diffs are standard 3.54 with standard transfer gears (not sure what they are 1.222:1 ???)

MYY-5T isuzu box
1st=5.315:1
2nd=3.053:1
3rd=1.655:1
4th=1:1
5th=0.721:1

transfer is
1.842:1

from what i know this seems like a good spread but i need opinions on the pro's and con's of this idea?

i believe it will be a way more useable range of gears since i find the lt85 being to tall in 1st gear compared to lt77,R380 and 6spd puma and 5th gear seems not much better than 4th

problems i can see are

*gearbox is probably shorter than land rover gboxes and will hence mean more acute front drive shaft angles
*gearbox is probably wider than the landrover gboxes
*will still need gear linkages looked at
*adaptors for bellhousing will need to be made as per most options

but if need be (most certain) i will need to get front and rear tail shafts made to suit but thats no big problem from what i see.

would love to hear any ideas or opinions as i am not familiar with this type of stuff

always wanted a 9speed roadranger gearbox (the more gears the merrier ) but when i found out there weight that was a no go option

^^^^^

For what its worth, I'd just get a Heavy duty LT85 from Aschrofts in the UK, saves all the heartache (expense!) and will likely do 200,000kms minimum, if I had a LT85 already that is