L series constant 4wd: centre diff lock activation

wagonist · Post by **wagonist** » Thu Jan 31, 2013 11:40 am

Currently, I'm installing a Vortex constant 4wd (with diff lock), single range box into my touring wagon. It's going to be lowered, rather than raised so not really worried about the low range, I would rather have the AWD.
I may have access to my old dismantled dual range, constant 4wd with diff lock box, but I have the same query regardless.

Normally, these are activated via a pair of electrically controlled vacuum solenoids. The Vortex one mounts near the wiper motor, and the L series one bolts to the left strut tower.
I've got the L series one sitting aorund somewhere maybe (its the same part as used on the part-time 4wd single range L series), but when I had the dual range box, I had issues with the centre lock engaging/disengaging.

I'm considering the use of something like a wiper motor instead to push/pull the cable. I'd have to set up some contact limits so that the circuit stops when full extension either way is reached (still working out that one), and work out if I reverse the polarity to the wiper motor, will it then spin backwards.

Thoughts/comments on this part?

The other query is about the load on the motor when the gears can't mesh. The vacuum actuator is always pulling in whatever direction is required, but then "slips in" when the teeth all line up, and then is supposed to continue to pull to keep it locked into whichever position. During this process, there would be load on the wiper motor but no movement.
Will this cause problems?

Will having a small movement range of the motor prematurely wear out the bushes/contacts for that region?
If so, should I look at setting up the mechanism so that it can do a 180 degree rotation for each movement required? Then it would spin "forwards" for a 1/2 turn to engage the diff lock, and by continuing the rotation in the same direction for the other 1/2 turn it would disengage.

Engage weapons and shoot holes in my theorising;)

Gannon · Post by **Gannon** » Thu Jan 31, 2013 2:23 pm

Interesting concept, I am actually going to undertake a similar approach when I get back into the RX. I have a Liberty dual range AWD gearbox and I want to make the Hi/Lo activation by push button, so I am going to rig up the vacuum articulator from a L series AWD box and make it operate the Lo range.

I really think the vacuum articulator will work better than a wiper motor, because of the issues you have already raised. There must have been a reason why it didnt work propperly, maybe something that will cause you similar issues with a wiper motor

Gimme a few months and I'll get into mine

tambox · Post by **tambox** » Thu Jan 31, 2013 3:49 pm

The constant force of the modulator is what makes this work.
Provided you are not spinning wheels when you try to engage the diff lock, it usually clicks in very quickly.
The load on the wiper motor would only be for a short time, provided you are on a surface when the wheels slip, slightly, to allow the teeth to line up.
If you are driving on a grippy surface where the wheels will not slip, unless pushed hard, it may take a while to engage or the teeth may not engage and just chatter (if the wheel speed difference is to high or the force is to much)

The vac mod is the easieist and more reliable than a lot of other methods.
Provided the modulator is adjusted correctly, the cable oiled a good Vac supply (in turbo set ups), they are fine.

Ive seen one done with a locking throttle cable/return spring, twist, pull out, twist again to lock.

Solenoid/return spring is another option.

Also remember what sort of road grime this system would be subject to.

wagonist · Post by **wagonist** » Thu Jan 31, 2013 4:53 pm

It was fitted to an EA82T engined touring wagon. I think the vacuum supply was the issue.
I probably should've plumbed it in after the reservoir on the firewall for the dash vents.
Or maybe installed a second one of them.

Will go back to looking into that option (but I'm going to have to find the solenoids:-(

Anyone know of a wreck of a GL FWD? I need the centre console without the hole for the low range lever.

Gannon · Post by **Gannon** » Thu Jan 31, 2013 5:04 pm

As for solenoids, any of the 2 port solenoids on an engine for emission control should do the job. The one on the strut tower on carby L series for activating the air con idle speed articulator comes to mind

wagonist wrote: Anyone know of a wreck of a GL FWD? I need the centre console without the hole for the low range lever.

So do I