Diff lockers - different types pro's & cons

Hi Troll 81 thanks for your comments. Have to agree that I like my ARB air lockers and not adverse to using them again. Bit like the devil you know, but at this stage I'm going to keep an open mind and way up options.

A full time locked diff. Is that right? Not familiar with the Lokka.

Phil (whats your name???)

This will explain it better than i can mate...Phil who ???????

About Lokka

Thanks mate

I will look further but with my mechanic beside me.

Personally until I get more info I would prefer the standard lockers which are operated by the driver by either air or haudraulic. The jury is still out for me.

Phil

Thanks for you comments guys. The option of a Lokka in the back and the ARB in the front hadn't occurred to me as an option.Well worth considering though.

vk1 dx from what I've been told the Lokka kicks in as soon as slip is felt in the non drive wheel. This way there is no need for the driver to turn on or off the locker.

From what I can gather being in the rear it would work even when you're not in 4wd but the front would need the hubs to be locked in before a front one would start to work.

I was thinking early this morning about the Lokka automatically coming into play and not being under control of the driver. I have heard that there is a common problem with diff locks where they can "encourage" the car to go straight ahead during sharp cornering. We wont go into the physics of it but it appears to me as being plausible.

Question: Assuming that the locker is engaged.
If the locker is not able to be cancelled by the driver, wouldn't a simple sharp slippery corner in the high country area be a real issue?

I know that would be an extreme case but we see them often in the high country around here.

Phil

Phil I mentioned that very thing with a mechanic who is looking over the vehicle I'm interested in. He was the one who suggested the Lokka as he has them in his vehicle and swears by them. I asked the question of loss of traction due to a slide or slip on a normal road? His reply was that if the car is sliding then there's a good chance the wheels aren't turning anyway so the traction control wouldn't grab.

My thoughts would be that if your car does go into a skid or slide the wheels would have been turning prior to the skid or slid and as soon as the differential registers the lack of traction then the Lokka would kick in.

I don't know maybe somebody who has a Lokka up front can explain what happens in such an uncontrolled situation?

I think that you missed my point. Nothing about slipping wheels. Rather a lack or disturbance to the steering when the rear diff engages.

Try it this way:
If you are on a sharp slippery corner (no wheels slipping) and the rear diff engages wouldn't that tend to make the car want to go straight ahead?

And as such if the driver can not disengage the diff isn't there a risk to control of the car by an automated system?

Phil

Yep missed your point Phil, and what you say does make more sense. Thanks

Phil, I can see what you are getting at and agree with you. In the conditions you are talking about the rear diff would not unlock which would cause the vehicle to do as you say.
I have read where other say the same will happen when a front diff is locked but I have found that since the wheels are generally facing in the direction you want to go you are better off, as both front wheels are pulling you around the corner.
Chris

Chris and Duncan (and any sand-bagger - remember that saying)

I thought that may be the case with the rear. But the front is a different matter. I don't think it would be the same as you say they are pointed where you want to go.

We may one day look at them (funds) and until then as I say the "jury is out".

Cheers

Phil

A locker is in fact an "unlocker". It is locked all the time and unlocks one click at at a time when axle windup gets to a certain level - so it doesn't all of a sudden lock up without driver input as it is already locked.

Garry

Hi Garry

That doesn't make sense to me.

I understand that a diff is locked when both axles rotate exactly the same as if they are the one shaft. Is that correct?

I thought that with an air operated locking diff that if the compressor is turned off the diff would be unlocked and the axles are free, to an extent, to rotate independently. Am I wrong?

You need to say more mate

Phil

Hi Phil, I'll have a crack at explaining "auto unlocker", using a diff ratio of 4 to 1 and just using the rear diff, NOT in 4WD



When you turn a corner with a normal diff, the wheels on the inside turn slower than the wheels on the outside, outside wheels still stay at 4 to 1, however to inside wheels turn slower to compensate the arc of the turn.

When you turn the same corner with a locked diff, both wheels will want to turn at the same speed,which is why you will get the "pushing sensation" thru the steering, both back wheels are fighting against each other, that's where airlockers come into play, having the ability to turn off.

With an auto locker when going straight ahead, the diff is locked, both wheels are turning at 4 to 1 compared to driveshaft, when you come to the same corner as mentioned, the INSIDE wheel stays turning at 4 to 1 (remembering, normal diff, wheel would slow down), the outside wheel then has to "speed up" releasing the ratchet mechanism.
The Autolocker will not allow any wheel to turn slower than what the driveshaft (4 to1) is turning at, it ONLY unlocks when one wheel begins to turn faster than 4 to 1.

Might take abit to get your head around, took me awhile

Shane

That's fine Shane.

I had an inkling that Garry may have been referring to the Lokka ones. So I thought that I should ask, just to be sure. Not a mistake Garry. Easy to miss. I thought that you were saying that ALL common 4WD differential locking mechanisms worked that way.

It is just another example of how the written word can be a tricky medium . In a face to face conversation he would see the concern in my body language and explain.

Maybe I am "stuck in the old ways" but I am having a growing preference for the non-automatic differentials. Imagine me in a driver less car - NO WAY.

No worries. Thanks for the time guys.

Phil

Shane is correct.
Some people have a problem with Lokkas making too much noise. There is clicking and banging going on when turning sharper corners. The solution is to turn up the radio. Some have also spun their car out going around a roundabout on a wet day. Having said that, other people love them.
For an elocker, try justdifferentials.com in the States, under $1000 shipped last time I looked. Cheers.

Thanks Mike

That's the type of things I have also heard.

Regarding importing one: I would prefer to get one locally with a warranty that I can trust. It's a long way to send it back if it breaks and the local importer refuses to help.

In any event I will trust the workshop where we got our work done. It may be a while even if we do actually get any.

Thanks for the tip though.

Phil.

Thanks for the comments Joe. Couple of mates have the ARB Lockers in their Troopies and are very happy with their operation.

Hi Dennis no I didn't give Toyota parts a thought. A mate has Toyota factory fitted lockers in his 80 series and has been very happy with them. Will have to give Mr Yota a call. Thanks

Thanks Rod I'd actually picked up a brochure so I was aware of the connection.

Thanks for the comments Michael, getting a bit longer in the teeth these days to be out playing, but I won't shy away from a challenge if out and about. As for mud -hate the stuff. Takes to long to clean the car afterwards.

Most of my driving is outback touring but want the option of full traction control when needed.

I havent got either type but i have researched the optios for my Patrol. From what i have read is that if you are exgaged (4x4) on unsealed roads at speed with a full time locker, you will be fighting the steering from left to right and when coming out of a turn, the steering returns to centre quickly. So the only option would be a part time locking diff i would think... Michael

Thanks for the comments Garry. The ELocker may be an option yet.

Thanks for the info Doug, but what is a TruTrack didn't spot that referenced in the article? I remember reading that article you've linked some time back.

Duncan
Sorry I did spell it wrong, it's Tru-trac, and they allow for easier turning when installed in the front diff, I have the full No-Spin Detroit in the front , it is a bit heavy on steering only when the hubs are locked,




.

Interesting video Doug. Good how they showed the different % of load shift depending on surface.

Tru-Track is not a locker - it is an aftermarket limited slip diff system - much better than an OEM LSD and certainly better than an open diff but nit as good as a locker.

garrycol
That's WHY you put them in the front, they are also recomended for full time 4x4 vehicles.

Morning Andrew and thanks for your thoughts. I agree with your wise old sage, also agree that lockers no matter what the type can get you into a whole lot of hurt quicker than no lockers but on the flip side they also help you get out of that sticky situation a whole lot easier too.

Have also heard that ARB systems can be subject to failure due to the electricts and air supply system. Have also read about seal failure also. Suppose that will be one of the distinct advantage over a mechanical system?

Hullo Duncs

If I recall correctly, the guy in Omeo talked about the air supply in/through the diffs being one of the problems with ARB lockers. And you are not relying on 2 systems - the compressor and the diff actuator. With the Elocker, there is just one well protected wire to activate the locker.

With respect to the Detroit Tru-Trac, I like the smooth and positive transfer of power between the wheels with no slipping clutch packs - see Doug T's video -and they are as strong as! Steering in marginal conditions is unaffected, with no understeer. You go where you point the wheels.

Cheers
Andrew

Morning gbc, sounds like your Lokkas were/are in the front and rear. How do they perform on slippery normal roads or when you hit that sudden puddle during a down pour? Very little chance of snow or ice on the roads here in Perth but you never know I might want to venture into Eastern regions where this can be problematic.

Never driven in snow or ice. I quite often pull in the front diff in heavy rain around town. No Ill effects with the lokkas. In powder sand etc you can feel the wheel with traction pulling sometimes which is a good thing. Without a locker the front would have had no traction otherwise. Air lockers are the best no argument, but they aren't that much better on a touring vehicle to justify in my case.

I would have to say then that your locker was not set up correctly. Was it a cheap and nasty Lokka brand or a proper locker like a Detroit?

I have had a Detroit in my truck for a number of years and you would not know it is there.

Yes it was a Lokka, cheap? yes, nasty? not really, they work well for what they are and are and in my opinion perfect in the front where they do not have to operate all the time as in the rear.
Having nothing to do with the newer type detroit I can not comment on them, but would assume that as with the Lokka, would take more to unlock when loaded i.e accelerating, therefore on a slippery surface you will not get enough difference in loading between the wheels to allow the diff to unlock.
This in not normally a problem when a Lokka is fitted to the front as the wheels are pointing in the direction you want to go and pullng you in the required direction, thats my take on it anyway.
Chris

Hi Bonz is the heavy steering constant or just when the Lokka engages?

So far the ELocker and the Lokka are grabbing my attention.

Chap who chimed in on my conversation with the OL chap said he had worked for the Harrop company for years and also swore by the ELocker's robustness & ease of use.

Mine is a lock-rite diff but as soon as you are in 4WD its engaged, and you can feel it in the steering, and I wouldnt call it heavy steering just that you know the locker is in and working.

Dunc

I have had a Lokka in the front of my Lux for almost 70,000 ks and would never be without one again. I agree with Bonz's assessment of them. It does make a slight difference to the steering but within a few minutes of using one for the first time, it starts to feel normal. I have used it on many outback roads and in the Simpson as well as a lot of Vic. High Country and other mountain tracks and it has never tried to pull the wheel out of my hands.

They work on the principle of the wheel with the shortest distance to travel is always being driven by engine applied torque. The wheel with the longest distance to travel is free to roll ahead. It is driven by road applied torque. It is rare for both wheels to be turning at exactly the same speed, particularly on mountain tracks, so they are almost always unlocked. The moment the driven wheel looses traction, it will lock. When one of them gains traction again, even if it is only one metre further along the track, it will start unlocking again.

This makes the car very easy to steer and also makes it possible to drive around a city all day with one in the rear. You can't do that with a manually locked diff.

They always drive at least one wheel, they can't drive no wheels and they can't drive both wheels while they are turning at different speeds like an open or LSD diff can. It is either one wheel at a time or locked.

The only issue with one in the rear on sealed roads is its ability to lock the moment a wheel looses traction can be dangerous. A good example is going around a right angle corner in rain and accelerating away too soon and too fast. The inside wheel will often spin in a situation like that and this will instantly lock the diff and maybe cause some rear wheel steering.

Incidents like that are most likely the reason why car manufacturers don't fit auto lockers as standard equipment. Too many drivers would get into trouble with them. Any driver who understands their operation and knows when they are likely to lock can adjust their driving style accordingly and should not have any problems.

I think anyone in your position who is trying to decide which way to go should try and learn exactly how a Lokka works in all situations before making a decision. They have their advantages and disadvantages just like everything else. There is also a hell of a lot of incorrect information about them on the net. I would not be surprised if many people who have not fully understood them have rejected them when they would have been ideal for their particular needs.

Thanks Splits that was a good explanation that even I could get my head around.

Splits! Interesting post of yours. i almost bought a Lokka online a few months ago and give it a go but i started researching them and the information varies wildly. As i mentioned above, i have had no experience with any style of locking diff so was at the mercy of the drivers that had. Its difficult to make a decision when there seems to be a huge difference of opinion. Some product for other uses mostly have an overwhelming good or no good apraisal, but not auto lockers. regards Michael

Michael it's almost like the Holden v Ford, Engel v Waeco, Yota v Nissan.

I think at the end of the day no matter what choice you go for their will be pros and cons and a margin of compromise, but as long as you are happy with your choice and the product does what you want it to do; who's to argue whether you're right or wrong.

As said below I'm now a whole lot more informed and a little less confused. Only time will tell!

Off topic and related to a previous thread about forum layout - it has just taken me about 5 minutes to go through the huge number of posts and followups to find this last followup yes I know it is all colour coded now but is still difficult to quickly find entries when it is a large thread.

Why do the owners of the site bite the bullet and just use the format that is used in many other forums where there is a button that simply takes you to the last entry - clearly in this forum the last post will be at the bottom of the thread but the last followup can be anywhere.

Garry

Hi Mick, 1Hz 1999 4.2L. At this stage anyway. Hope yo also bolt on a turbo.

Had new and pretty in the past now I want something to do up and not be concerned about breaking something if I go off-road. Got a bit tired of the low clearance and plastic parts on my Terracan, even though it is a magic vehicle.