Isuzu MSA gearbox into 6x6

[123rover50]

Many years ago now I fitted an Isuzu MSA 5G gearbox into my 6x6 Camper conversion of a prototype project Perentie chassis.
Sheldon designed the adapter housing to the LT95 T,box to keep the 6x6 facility.
All has been well for thousands of K,s untill the last trip the box started to get hard to change gears in. We got home with only 4th gear selectable.
I suspected the nut on the end of the mainshaft had come loose and on inspection I was right.
My fault, I had not staked it deep enough.
Buying a WSM it states the first of them were not staked at all.
Then they staked into one groove and the latest are staked into two grooves.
This leads me to believe there was a problem with this nut working loose.
I have just swapped to a spare box and while everything is out thought I would post a few photos of how it looks.
So if you want to ditch that LT95 and go for a 5 speed for your 6x6 this is how its done.
Sheldon might do you the housing or make your own.

[ozeraser]

Thanks mate, I have a similar setup 4bd1 msa and series transfer box,, nice to get an idea of what it looks like off.

[123rover50]

The extension housing has a division with a seal in it.
https://www.aulro.com/afvb/images/imported/2016/11/475.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1880_zpsp2jferda.jpg.html)

https://www.aulro.com/afvb/images/imported/2016/11/476.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1882_zpsbrif8lhu.jpg.html)


Bolted up.

https://www.aulro.com/afvb/images/imported/2016/11/477.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1889_zpsh16jwbbc.jpg.html)

Drive flange on. And made sure its staked this time
https://www.aulro.com/afvb/images/imported/2016/11/478.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1890_zpsvwdqtqma.jpg.html)

Last time I staked it through the back. This time I drilled and tapped a half inch hole above where the nut is and staked it with a blunted small cold chisel.

Adapter flange bolted up.
https://www.aulro.com/afvb/images/imported/2016/11/479.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1891_zpsbfnx6yrq.jpg.html)

Keith

[workingonit]

Thanks for posting 123Rover50.

I'm probably not understanding something. How can the staked nut in the photo be responsible for gear change difficulties? Working with my setup the nut would seem to be there simply to hold the drive flange in place.

The photo perspective had me fooled, but I now see the grooves in the adapter are very coarse by the peaks just in the right of frame.

[123rover50]

Thanks for posting 123Rover50.

I'm probably not understanding something. How can the staked nut in the photo be responsible for gear change difficulties? Working with my setup the nut would seem to be there simply to hold the drive flange in place.

The photo perspective had me fooled, but I now see the grooves in the adapter are very coarse by the peaks just in the right of frame.

You are right. I dont understand it either. The nut had worked loose and I thought that may have let the shaft move back and forth.
Something has worn because the rearmost gear has about 4mm of end play whereas the replacement box gear has only 1 mm or so.

[123rover50]

The LT 95 WSM states the spacer and transfer gear should be locktited to the shaft. Of all the boxes I have stripped not one was tight and all showed some flogging of the shaft splines.
This time I thought I would cut some grooves to make it easier for oil to get in and see if that makes a difference.
https://www.aulro.com/afvb/images/imported/2016/11/453.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1895_zpshtzgmq4x.jpg.html)
https://www.aulro.com/afvb/images/imported/2016/11/454.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1896_zpsrclcsry0.jpg.html)

Keith

[Bearman]

Just looking at the spline wear in the shoulders of those gear splines I wouldn't reuse that gear Keith. It is going to have slop there when you accellerate/decellerate unless you loctite it. Even with loctite it will probably eventually loosen. It's important to loctite the sleeve/spacer as unless you do it will remain stationary inside the seal while the shaft turns and act like an oil pump and transfer oil from the transfer to the gearbox. I would also check the mainshaft splines for wear where the gear sits on it.

[Bearman]

I had better rephrase my last post - the transfer oil will end up in the adaptor instead of the gearbox as I stated!!!
Any chance of a photo of the front of the T/C where the adaptor bolts on Keith?
Did you machine/drill the front yourself or get someone else to do it.

[workingonit]

I'm a novice re contact patterns, but the top photo seems to show the contact is well inside the tooth length; yet seemingly worn at the other end. Mismatching contact due to worn shimming?

[123rover50]

I had better rephrase my last post - the transfer oil will end up in the adaptor instead of the gearbox as I stated!!!
Any chance of a photo of the front of the T/C where the adaptor bolts on Keith?
Did you machine/drill the front yourself or get someone else to do it.

I cut it off with an angle grinder, then sat the back end on the mill table and milled it flat, and square. Here is a pick of when I set it up way back when I was putting the auto box in it.
Dont have a pic from the front sorry.
https://www.aulro.com/afvb/images/imported/2016/11/410.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_0024.jpg.html)

Keith

[123rover50]

I made the adapter housing so I can keep oil in it with a fill, level and drain plug. Try to keep the splines from fretting.
No pic of the front but here are a couple of the two bolted together.
Good point Brian , on the sleeve. I might locktite that.

https://www.aulro.com/afvb/images/imported/2016/11/408.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1900_zpszp5gfols.jpg.html)

https://www.aulro.com/afvb/images/imported/2016/11/409.jpg (http://s939.photobucket.com/user/123rover50/media/6x6/IMG_1899_zpsjtxllsyc.jpg.html)

Keith

[Jitterbug]

Awesome info Keith, thanks for posting!

I am about to start the process of converting my lt95 6x6 over to an MSA, planning a Brisbane to WA trip later in the year and I have had enough of the the 4 speed!

Keith, where abouts in QLD are you, I would love to have a chat about what you did with yours, I am in Brisbane so hopefully not too far away!

Sheldon, do you still have the drawings to make up another adaptor? (will PM in case you dont see this)

I am going to try and acquire a dead LT95 that I can do the chopping on so I can build the new MSA/95 box without taking the camper off the road, if anyone can point me in the direction of one, that would be great!

Finally, if I am going to all this effort, which is the best MSA to go for (I have 4.1 diffs and 33" tyres)? My 4bd1t was originally out of a truck so I still have the bell housing / clutch / flywheel that came with it.

Thanks for the help!

Dave

[123rover50]

Dave.
PM sent.

Keith

[Vern]

Dave i would go for the msa5r, it has a taller 1st and 5th gear but the same 2nd, 3rd and 4th as the msa5g, it wouls go better with the .966 lt95, 4.1 and 33's. Or you could even look at a splitter box.
Best to give Sheldon a call perhaps.

[Jitterbug]

Dave i would go for the msa5r, it has a taller 1st and 5th gear but the same 2nd, 3rd and 4th as the msa5g, it wouls go better with the .966 lt95, 4.1 and 33's. Or you could even look at a splitter box.
Best to give Sheldon a call perhaps.

Thanks Vern, tried to direct message Sheldon but his inbox is full, hopefully he sees this soon!

Dave

[Vern]

Thanks Vern, tried to direct message Sheldon but his inbox is full, hopefully he sees this soon!

Dave
I will send him a text. Or you could look up his business and call him.
COR Conversions

[workingonit]

Sheldon is 0488474020

[123rover50]

Try and get the LT95 ex army with the tapered roller T,box.
Are Grays still selling them or are they all gone.
If Sheldon will do you another adapter housing I might get another for the other FC I have. Swap the LT 95 in it for another MSA.
Its on 900x16,s with 4.7 diffs so I will get better road speed[smilebigeye]

Keith