ARB Diff Lock Sequence

[Tank]

My front ARB diff lock won't engage unless the rear ARB diff lock is engaged, I only noticed this the other day when I was servicing Disco.
If I am traversing a rugged slippery section of ground and I think it needs both diffs locked (not often) I hit both switches at once, if I have to make a sharp turn or the going gets easier, I turn off the front diff lock, so I have never actually used the front diff lock without the rear diff locked.
Is this how ARB build them so that you cant lock the front diff without having the rear locked as well, not refferring to single locker setup in front diff only, front and rear only, Regards Frank

[Blknight.aus]

nope thats just a switching thing.

your rear diff should power up the compressor and the rear diff lock
and the front one will only power up the solenoid to the front diff, if the rears isnt on then the compressor wont be running to actuate it. It might also be electrically wired so that you cant turn on the front one without the rear.

in either case its not a big job to rewire the swithces so that the compressor comes on with both or so that both are independant of each other.

[Slunnie]

Not quite like that.

The compressor is on it's own switch and can be turned on and off as required eg for pumping up tyres. You need the aircompressor on to turn the rear difflock on though, and you need the rear difflock to be on to turn the front diff lock on. You can't just run the air compressor and the front difflock without the rear. The front drivetrain isn't as strong as the rear, so it's just a method that ARB has built in to minimise damage. There are some pretty simple modifications to the loom that can be made to over-ride this and allow independent locker control, though I've never made them.

[Blknight.aus]

Last setup I saw had the rear diff and the compressor operated on the one switch albeit a center off double throw type that was compressor on one side and compressor and diff lock on the other...

Im guessing then that thats not a normal setup and the electrically dependant configuration is more the norm...

[Tank]

Dave, mine is setup like Slunnie said, I have been using it for 2 years now and I only noticed the way it is the other day when doing some servicing when I had the ARB compressor running and accidently bumped the Front locker switch and nothing happened, when you think of it, it's a good idea, Thanks, Regards Frank.

[Slunnie]

Hmmm, thats interesting. I wonder if its a new swtich and loom then? The normal switches are just double pole double throw, this other one sounds like its doule pole triple throw.

[Blknight.aus]

the setup didnt look like it was using the stock ARB switching the bloke had the diffs installed by them so It might have been a custom fit to his vehicle, If hes still around (he was here on course) I'll go get pics for you when I get back from cooma....

makes sense to me to do it with 2 swithces one for the compressor and front diff and then one for the front..

[WOLLAPIT85]

Not quite like that.

The compressor is on it's own switch and can be turned on and off as required eg for pumping up tyres. You need the aircompressor on to turn the rear difflock on though, and you need the rear difflock to be on to turn the front diff lock on. You can't just run the air compressor and the front difflock without the rear. The front drivetrain isn't as strong as the rear, so it's just a method that ARB has built in to minimise damage. There are some pretty simple modifications to the loom that can be made to over-ride this and allow independent locker control, though I've never made them.

Slunnie is correct.
This is the way that arb have designed it. It is a safety thing.
It is just a matter of leaving of one of the wires off and crossing from one to another to change it so you can operate either..I would need to pull my switches to tell you what goes where.

[rovercare]

the setup didnt look like it was using the stock ARB switching the bloke had the diffs installed by them so It might have been a custom fit to his vehicle, If hes still around (he was here on course) I'll go get pics for you when I get back from cooma....

makes sense to me to do it with 2 swithces one for the compressor and front diff and then one for the front..

No it doesn't make sense, especially to operate the rear solenoid when the air is low, the 80-110psi needed to overcome spring pressure in the locker, should be instantaneous, wouldn't want the dogs trying to half engage;)

[rovercare]

Slunnie is correct.
This is the way that arb have designed it. It is a safety thing.
It is just a matter of leaving of one of the wires off and crossing from one to another to change it so you can operate either..I would need to pull my switches to tell you what goes where.

Yep, just a simple wiring change, I regularaly use my front before the rear

[LandyAndy]

As the others state.
Its normal,you can only lock the front if the rear is locked.
Its how it is!!!
Andrew

[DiscoDan]

If you have the stndard loom you need to link the wire from your rear switch (pin 2) to your front switch (pin 2)

As it currently sits the red wire (power out) leaves compressor switch from pin 3 and feeds power to pin 2 on your rear locker switch (thus locker won't work unless compessor on) A yellow wire is then triggered and this feeds the power to pin 2 on your front locker.

To over come this splice into the red wire (pin 3) from your compressor switch and run it to both locker switches pins 2.

I just fitted the new compressor and although I haven't done it yet I will be trying it in the standard arb way first.

The old set up I had i could run either or both as desired

Hope this helps

Danny

[Rad97]

I have arb front and rear difflocks and seperate compressor switch and my front diff lock only activates when the rear is in aswell.

I think it maybe the way arb set them up must be some safety reason or mechanical failure reason.

[rovercare]

I have arb front and rear difflocks and seperate compressor switch and my front diff lock only activates when the rear is in aswell.

I think it maybe the way arb set them up must be some safety reason or mechanical failure reason.

Did you read the whole thread???????:p

[weeds]

a mate of mine has changes his wiring so that he can select the front only or the rear only or both

i was going to do the same but as i hardly get a chance to use the locker i have not bothered modding mine

come to think of it i cannot recall a situation where i would have preferred to engage the front locker only

[Slunnie]

come to think of it i cannot recall a situation where i would have preferred to engage the front locker only
I'm the same, but it would be nice to have that flexibility.

[rovercare]

I'm the same, but it would be nice to have that flexibility.

Good for driving over trees and stuff, getting the nose up embankments, its not that often, but it is very handy;)

[DaveS3]

Steep hills

Front locker will hold the car better and give more controllable/steerable drive without the back of the car pushing you where you shouldn't be.

Dave.