[husq2100]

you could also try the "heavily modified Land Rovers" page on FB

 

[mdlimy55]

you could also try the "heavily modified Land Rovers" page on FB

I had no idea about this group, thanks! Just joined it.

I hate that forums are dying and everything is moving to facebook. Ill keep updating this forum on progress. Havent picked up the 1339 from my buddy yet, hopefully as soon as this stupid pandemic cools off.

 

[LR Max]

I would think the best way would be to get a roamerdrive and swap the planetary gearsets. All the other engineering is done. Would be a good prototype, then maybe make a deal with roamerdrive to buy select parts (case, linkages, the part that sticks into the transfer case, etc). But overall, except for the gear ratio, EVERYTHING is there. Even getting a 1.50 or 2.00 gear ratio reduction would be huge. Not like we need to go all 22re 598379482:1 crawl ratio.

I was just looking at a cutaway for the Fairey. Kinda wish I had kept my old one. I think turning it into an underdrive would be semi-simple assuming I could find someone to cut a new countershaft for me and weld on the case. That said old series overdrives are junk. Mine ran on metal shavings.

 

[100SRV]

I would think the best way would be to get a roamerdrive and swap the planetary gearsets. All the other engineering is done. Would be a good prototype, then maybe make a deal with roamerdrive to buy select parts (case, linkages, the part that sticks into the transfer case, etc). But overall, except for the gear ratio, EVERYTHING is there. Even getting a 1.50 or 2.00 gear ratio reduction would be huge. Not like we need to go all 22re 598379482:1 crawl ratio.

^That is a great idea!
I pondered running a hydraulic pump / motor set up taking advantage of the axial flow variable displacement type motors. The sheer bulk and mass of the components, cooler, oil tank is way more complex than a simple underdrive, costly too.

 

[Erik - LR Series V8]

I see this is an old topic but have an idea for a crawler box would like to run past everyone for their input. (This is also my first time I have ever joined an online form but really looking for an additional lower gear so I need to reach out)
Cost might not be reasonable for my idea,
I did spend a bit of time searching online for an Ashcroft underdrive but how rare these are and some of the prices being asked I started looking into alternatives.

Idea:
Mount a Northwest Fab Blackbox.
In my setup I have an LT85 transmission with a LT230 tranfercase. (3.9 V8)
There is an adapter available from Axis Industries that adapts a round bolt pattern to the LT230.
For mounting the Blackbox this adapter looks to be able to be used based on the bolt pattern.
Would use the Axis adapter as the basis to make a template to mount the Blackbox to the LT85.
Would need a shaft (stub shaft) to adapt the LT85 10 spline output to the input splines available for the Blackbox.
I have not done a lot of research into input shaft diameters but if I could find out the outer diameter of lets say the 29 spline Allison input shaft, this could be machined out to slide over the 10 spline LR shaft. But for the donor shaft to be machined would have to research costs what input shaft is affordable to use. (And machining cost)

One issue will be what is the length of this setup.
I have not done any real measurement so far but just looking at my 109 Series Land Rover, I might have to do some chassis cross member mods but this would not be an issue for me.

Blackbox length spec I could find lists 7 1/2"
Axis adapter = 1"
Custom adapter to be made based on axis adapter patten - length ?

For shifting the LT230 High/Low and shifting the center diff the current mechanical lever would not be able to be used due to moving back to the LT230, to resolve this would run cable shifters. (1 for H/L and 1 for center diff)
I have seen brackets for a cable shifter that already exist for the LR Discovery 2 that mount on the LT230.

My budget would be in the $3500-$4000 range. (For all parts required, machine work and new drive shafts) I think this is a realistic cost range based on seeing the Blackbox price and the Axis Adapter Price (Axis adapter is fairly high priced considering its just an adapter, I know there are a couple more option for adapters will still have to look into)
(Maybe the Axis Adapter could be purchased without the bearing, just need the adapter and the shaft, the Blackbox has bearings for both the front input and rear output of the box so no need for a bearing in the adapter.)

I will continue to do research on this and my goal is to start getting into this project next year once I know this idea will work.

If anyone has any comments, positive or negative, let me know.

Looking for advise also on the input shaft adapter, Land Rover 10 spline to whatever spline the Blackbox can accept anyone have any experience with this?

 

[red90rover]

Why not just get the 5:1 low range gears for the LT230?

 

[Landy_Andy]

Depending upon where you are, a GM GenIII, NV4500, doubler, Nicks adaptor & LT230 will give you a 180.71:1 in low, low gear plus about 300bhp to get into trouble with.... if you have access to junk yards it can be done for quite cheap. Just another option.

 

[mdlimy55]

Bringing this one back from the dead. Been printing prototype pieces to verify design/fitment. Done a little shaft machining, more to go up next.
Looks like a series drum should fit like bill mentioned. I might not mess with it on this one, more interested in setting up a driveline disconnect for this particular build.
Adapter will be about 1/8” longer to give some more clearance on the intermediate shaft/nut. Next up is to take some proper measurements for total input shaft length, then finish machining both gears for assembly and welding.

 

[nykvlv]

Bringing this one back from the dead. Been printing prototype pieces to verify design/fitment. Done a little shaft machining, more to go up next.
Looks like a series drum should fit like bill mentioned. I might not mess with it on this one, more interested in setting up a driveline disconnect for this particular build.
Adapter will be about 1/8” longer to give some more clearance on the intermediate shaft/nut. Next up is to take some proper measurements for total input shaft length, then finish machining both gears for assembly and welding.

Any progress with this awesomeness?
Did you make it work?
I would love to get one

 

[Ziv_300tdi]

This is brilliant, did it work?
Do you have some more info?