Difflock functioning

[Johann 1984]

Hi Guys,

A quick question:

My vehicle has 40 000 km's on the dial. For the first time ever, I attempted to use my difflock this December in Botswana after getting myself properly bogged-down and stuck in one hell of a mudpit.

After recognising that I was completely immobile and wheels were just turning mud, I releases the fuel pedal, put the Patrol in neutral, switched on the rear-difflock and started rocking the car back-forth untill I was able to get unstuck. The difflock indicator just kept flickering. At no point did I hear the locker engage and make that 'clingy' clamping sound. Thus, I discovered that the locker were not engaged while I was thinking it did. After this episode, I consulted the manual and read that the difflock indicator on the dash should appear without flickering to indicate engagement. I then experimented with the difflock to test if it actually will engage. So I put the Patrol in 4L, engaged locker, 1st gear and let it idle down the dirt road of Savuti. After I guess 20 meters or so of idling, the difflock indicator light on the dash was still only flashing, indicating that it has not yet engaged. Only after attempting to turn the vehicle to the right quite sharp did I hear the familiar 'clacking' sound of the locker engaging. Then the flashing difflock indicator light stopped flashing and became solid. Thus I at least knew it did work.

My question however:
1. How long does it normally take for the locker to engage? Shouldn't it be instant?
2. I read that you should test your locker safely on regular intervals otherwise it may become hesitant to engage after years of non-use. Is this true?
3. Is the front diff an open diff or does it have Active Braking Limited Slip Diff?

Thanks!

Johann

[Alex Roux]

Hi Johan

The short answers:
It should be pretty quickly to engage. Sometimes it may take a while, especially if it is not used frequently.
That, I guess answers your second question. I test mine whenever I get the chance. But I only drive my car once a week. That is when I engage and disengage.
There is a rumour, which I have not been able to confirm, that the later 4.8 Grx's have LSD on the front diff. I would be keen to hear others' view on this.

Alsos note that the indicator may continue to flash, while the locker is in fact engaged. There is an indicator switch that is seperate from the actuator. Typically the indicator switch has a tendency to get stuck rather than the actuator switch, if not activated frequently.

[Peter Connan]

Johann, you don't say exactly what Trollie you have, and your signature says it's a hardbody.

However:
The Patrol diff lock has few, large teeth. Therefore it may need quite a lot of relative motion to lock it up. In mud like that (no traction), it might never engage.

Yes, the Patrol's diff needs to be exercised on a regular basis. The solenoid can get sticky otherwise.

It has an open front diff, and no LSD or tracion control.

[Brett Bignoux]

Johann, your diff lock will not always lock instantly, the diff needs to work a bit for the dog clutch to align and engage to lock. The solenoids for your diff lock do on occasion get stuck, also delaying the engagement of the diff lock. The solenoids also sieze with rust when there is too much moisture in the vacuum line from lack of use. Activate your diff lock about once a month, or GO 4X4ING that's even better !

[Johann 1984]

Hi Alex,

Thanks for the explanation. I found a few comments on the Aussie Patrol Forum as well, link attached:

http://www.nissanpatrol.com.au/forums/a ... 14502.html

I'm considering fitting a locker to the front axle as well. Does any bloke on this platform perhaps have a front locker? Also, what is a budget option yet reliable? I know ARB air-lockers are the be-all end-all of quality and the TJM lockers are absent following the whole fiasco last year. I have read that OL stock lockers. Any know-how on that? Or any other types you guys may know off? Lastly, what's the difference between standard and air-lockers???

You guys Rock

Johann

[Johann 1984]

Hi Peter,

I have a 3.0 GL. It's a 2013 model. I use to drive a lovely YD25 2012 Hardbody but I sold it. Should the locker make a slight sound when engaging? Or silent? I'm sure I heard a slight sound. My mates cruiser 76 makes one healthy loud 'clack' sou d when his lockers engage.


Regards

Johann

[Alex Roux]

I hear a clack when mine engages. But it is rather soft. Not to be mistaken for the click made by the front auto locking hubs when changing direction while in 4x4 (if the hubs are not manually locked).
I have also heard of others saying that they do not hear theirs clack at all.

The ARB air lockers is probably the safe route, given the wide spread use and therefore support you will get for it.
But I have also heard of the magnetically engaged lockers, which I think is a better technology, but not common in SA.

Standard vs Air locker:
The standard locker if used correctly is pretty good. Where it has broken, this typically happens when driving off thinking it had already engaged, when it has not done so yet.
Once engaged it will not break unless you try too hard and abuse the vehicle in an obstacle (my view).
It has, as Peter says, only a few large teeth.
I understand that the ARB air lockers has more teeth and is stronger. But it is not full proof since it still relies on an air tight pipe from the compressor to the diff, to engage.
In an obstacle, if only one wheel has traction, and you are stuck, using too much power while the diff is locked, can result in serious damage elsewhere in the drive train.
Therefore, I suspect, if you have a choice, it would be better for the the standard locker to break rather than the side shaft to bend of the prop shaft to break off.
Having a super strong diff locker is therefore not necessarily such a good thing...
The weakest link in your drivetrain should be one that can break, allowing you still to drive home.

As far as I know Thabbies and Offroadbiker on this forum have front lockers.

[Clem]

the later 4.8 Grx's have LSD on the front diff. I would be keen to hear others' view on this.

It's not true. I have a 2013 and I can tell you that it does not.

[Marino4x4]

Hi Johann

The standard locker on the Patrol works with vacuum from the engine. The ARB air locker needs an extra compressor fitted because it uses positive air pressure to engage. There are also options on the market that works with electromagnets like the Toyota's do.

Here is a picture of the diff lock: http://patrol4x4.co.za/viewtopic.php?f= ... ken#p41377

You can see that it might happen that the shafts will need to rotate at different speeds to allow the teeth to engage. When driving down a straight road the wheels will turn the same speed, but when you took the turn the speed varied and the diff could engage. In mud it is difficult to tern and let the wheels move at different speeds, but you can maybe try next time to make a turn until it engages.

Show us some pictures of your trip.

[offroadbiker]

Got the ARB lockers in front with the additional compressor - problem, well I never seem to get a chance to use it, the patrol does not get stuck