⚙️Project: rear difflock manual conversion (1 Viewer)

[TheComedian]

After my motor of the rear differential lock is unfortunately only crumbs ( Rear Lock still flashing - https://forum.ih8mud.com/threads/rear-lock-still-flashing.1267554/), I was now faced with the choice of whether I buy a new actuator or a lock from ARB.
The new actuator would cost 500€ and the ARB system 1600€ upwards with long months of waiting time which is also much more prone to failure than the Toyota system.

Both suck... so I thought I'd act according to KISS. Simply by hand and manually.

Briefly measured the disassembled old housing and checked with the 3D printer whether I'm about right (it's a car, it's not about hundredths of a millimeter).

Fits.

So the next step was to spend an hour on the CAD program, drink coffee, and spend twice that time rendering a video again.

The whole system is realized with a Bowden cable that works on tension and compression. The end of the Bowden cable will end somewhere in the driver's compartment.


Currently I have a prototype printed with which I can then try out the parts. If that works then I will mill the whole thing from aluminum or steel on Monday.

 

[CharlieS]

This is awesome! If it works out, you should also post to the 100 series board since the 1998-2002 100 series in the US use the same exact actuator.

 

[linuxgod]

Interesting. My main concern would be stretching of the cable over time. It would suck if it de-activated while you needed it (or activated when you didn't), but I'd be more concerned with it not fully engaging or disengaging partially. Maybe I'm overthinking that problem though. In any case I assume this could in part be solved with high quality cable and/or "pre-stretching" it, or providing for some sort of adjustment screw like the e-brake has.

 

[TheComedian]

Interesting. My main concern would be stretching of the cable over time. It would suck if it de-activated while you needed it (or activated when you didn't), but I'd be more concerned with it not fully engaging or disengaging partially. Maybe I'm overthinking that problem though. In any case I assume this could in part be solved with high quality cable and/or "pre-stretching" it, or providing for some sort of adjustment screw like the e-brake has.

Good points.
But this is why I use a bowden for tension and compresion. They are different to normal ones. Its 2mm spring steel and no classic cable. So the only point would be the streching with higher temperaturs.

 

[CharlieS]

I'm pretty sure other older 4x4 use a bowden cable setup, so this seems like a reasonable experiment to me.

 

[bronc076]

Very cool!

 

[saucebox]

Super interested also—not having to rebuild the factory motor (again) sounds amazing.

It's a different concern entirely, but some of the early trucks (60 series, 70 series, probably more) had factory cable lockers. Combining some of those factory interior parts with your cabling and housing could make for a fun retrofit.

 

[clrussell]

Very cool. Watching

 

[ntsqd]

Control cables are a commercial commodity, they are wear replacement required items, but (at least in the US) they're not hard to find. A simple search should show many vendors of these cables. The common brand name used to be "Morse." Sticking to std. attachment and housing anchoring designs should make this an easy thing. IME the more difficult thing is sealing the assembly from dirt and debris.

No familiarity with the LC200's locker, will a detent or a position lock be required for either or both positions?

I know that OX had to design in some float as their first generation shifter design was fixed at both ends of the lever's motion, and that caused some problems that took a while to show up. A friend has one of their very earliest Dana 30 lockers and had the first gen shifter. He liked and had no problems with it, but they tracked him down and replaced it with the second gen shifter (excellent CS!).

Seems like once you can effect the lock/unlock with a cable that you can then actuate that cable with lever, an air cylinder, a stepper motor, or even a linear actuator depending on the level of complexity that you require.

 

[bloc]

Any thoughts toward some kind of ball/spring detent system to keep it in each position?

I vaguely remember something about a commercial cable actuator adapter for the old toyota 8” e-lock diffs. Marlin or someone along those lines. Might be worth looking into for their ideas/tweaks.

Either way this is really cool.

 

[ntsqd]

OX Locker shifter, $90US: Manual Shift Lever - OX Offroad - https://ox-usa.com/product/manual-shift-lever/

 

[TheComedian]

A lot of good Ideas
@ntsqd a lever like this would be nice but atm I didn’t find one like this here in my region. Especially in this size.
Atm I ordered one of these

@bloc
The ball/spring combination is a good idea, but it would also bring more complexity into an area where I want less complexity.
In addition, I would also have to machine the control rod extra on the lathe for the appropriate notch.
But it's certainly not a bad idea to make sure the rod is retracted so the differential doesn't lock unexpectedly. I try to do this more in the driver's compartment where there is less dirt causing problems for the mechanism.

@ntsqd
a extra cylinder, actuator, motor or something else would just bring me back to what i had bevore. I mean the rear diff lock is something you just need all few years with the 200 also in heavy wheeling.
What could be easier than just push the switch (the upper picture) by hand down when I need this.
This fits perfectly for a Africa-Version LC200 manual shifter ;D

 

[kwelhand]

Very very cool!
Love your KISS approach.

 

[ntsqd]

My thinking is that with the cable that any such more complicated actuation method can be inside the vehicle out of the muck and dirt. I went direct air with the soon to be deployed OX locker in my FSB, but if it gives me trouble I'll be ordering the shifter that I linked and a cable.

Some versions of that pull knob have an internal course thread and the knob spins to push or pull the cable (w/o also spinning the cable itself), or you can push the button in the middle of the knob to by-pass the threads and push or pull the cable directly. Bonus is that the knob stays where ever you set it due to those threads. They're made for use in hand throttle situations like aircraft and stationary engines.

 

[TheComedian]

I have just added a few details. Among other things, a centering between the main part and the adapter / cover and the groove and the grub screw to fix the rod.

 

[bjowett]

A great project, thank you for sharing. I've built a several cable conversions throughout the years, they work very well.

 

[TheComedian]

Today I got the milled components and later I'll start to assemble everything.

 

[ntsqd]

If those are stainless SHCS you may want to re-think them. Hard to tell in the picture.

SST fasteners threaded into Aluminum is strictly avoided in marine environments because they are far enough apart in the electron potential scale that a little moisture and it becomes a battery that will irrevocably seize the fasteners in the aluminum.

Unclear on if this still happens when the AL is anodized. I would expect so, but at a slower rate because it will only start to occur where the anodize is scratched or worm thru by the fastener.

I have found that I can source plated alloy steel SHCS and I now use those exclusively in all of my production tooling assemblies. Avoids the problem, they don't rust like the black oxide coated SHCS', and they're markedly stronger than the SST fasteners as well.

 

[TheComedian]

If those are stainless SHCS you may want to re-think them. Hard to tell in the picture.

SST fasteners threaded into Aluminum is strictly avoided in marine environments because they are far enough apart in the electron potential scale that a little moisture and it becomes a battery that will irrevocably seize the fasteners in the aluminum.

Unclear on if this still happens when the AL is anodized. I would expect so, but at a slower rate because it will only start to occur where the anodize is scratched or worm thru by the fastener.

I have found that I can source plated alloy steel SHCS and I now use those exclusively in all of my production tooling assemblies. Avoids the problem, they don't rust like the black oxide coated SHCS', and they're markedly stronger than the SST fasteners as well.

Nah they are normal galvanized screws.
And even if they are. Its sealed with Loctite and when everything works there comes some grease around everything or corrosion x-hd.
I use this combination pretty often and even with stainless its not a big deal in this area of the car if you take a little bit of care.

In the maritime field or where components are exposed to water for a long time, I completely agree with you that such a material pairing of a very noble and a base material naturally turns a component into an anode. This is also the reason why I like to use zinc plated screws. They last longer than normal or burnished steel but it at least first eat away the galvanized part in case of emergency

 

[TheComedian]

Some new pictures. Final test follows tomorrow