how to use LC diff lock?

[MrPaul]

As I have never driven a LC before, I am wondering how to use the differential gears because I don't want to look stupid at a potential purchase without knowing how to engage them and when.

I have looked everywhere for a tutorial to no avail. Can somebody put my straight and give a brief description on what to do.

 

[adrianr]

HI there

not sure of which LC you have?

Meantime you might have a read of this article to get your head around some basic mechanical terminology:
http://www.lcool.org/technical/diffs/diffs.html

On a loose surface the power will go to the wheel with the least grip so you could think of it this simplistic way:
Your 4wd is really 1 wheel drive until you start to lock the differentials
centre lock and you have a 2wd - power to front and rear.
lock the rear and you have 3wd
lock the front and you have 4wd

For me centre diff lock on anything loose - gravel, track, mud snow ice

rear locker if you need more traction (set it all in place in advance ie before you will need it - read the conditions ahead). only use lockers when you are going slowly and preferably straight as possible - the more locks you apply on the transmission the more the truck wil want to go straight on. Read up on transmission wind up.

front locker if you have one - to get you back out of where you should never have gone in the first place ;-) or need to keep going to get back out the other side.

Using lockers puts incredible load on your transmission components so would suggest you get a good understanding of what and when, and be as gentle as you can/ conditions allow. With careful thought you can get through most anything, but understanding how things work, what they are for and when should prevent you from sitting there wishing you could rewind the clock a few minutes...

Also read up on dropping tyre pressure to enhance grip (you'll need a way to get the buggers back up again afterwards).

Also make sure your choice of rubber is suitable for the task at hand.

Working out your correct route, coupled with low tyre pressures, and working your diffs etc will allow the truck to do things that will probably take your breath away, again and again.

Welcome by the way!!

 

[Chris]

Surprised that a search on here didn't turn up anything. It's been covered many times. But here's a beginners guide. Some of this depends on which Cruiser you are talking about though.

Guys - talking in general terms here. If this isn't how a 60 year old 40 series works then sorry, but go suck a rat, OK?

Crusiers are proper 4x4s designed so that all the drive train is really smooth and happy on all surfaces. Some other makes are more cheaply built and uses a lesser 4x4 mechanism whic is only part time 4x4 because they are NOT always happy on all surfaces and they get a bit tight and squeaky leading to broken bits. The Cruiser has a differential for the back wheels, one for the front wheels and a third proper differential in the middle. Usually in the middle differential there is a thing called a viscous coupling. This is a sort of friction device that makes sure the front wheels get drive as well as the back one. But when the going gets tough, the front wheels lose drive at times and you are effectively only in 2 wheel drive, in a way. So, there is manual override setting that locks that slippy coupling solid to get the drive back again. On MOST cruisers this is a lever next to the gear shift. Pushing this forward moves you from High range (road gears) open diff to High range locked diff. Usually this can be done whilst moving. Some models have a dashboard button to control this. OK.

Now if things get even more slippy, the left and right side of the car can be affected not just the front and the back. So, there is the option to lock the rear two wheels together. But, MOST models only allow this once you have locked the middle and THEN gone into low ration - off road mode. This is USUALLY done with the same small gear lever which goes forward, across and forward. Then there will be a dial (usually) that you rotate to lock the rear diff. On the dash, you will see a flashing orange light for the middle diff which should go solid when locked and then a flashing red light which turns solid to tell you that the rear lock has engaged. Sometime you have to back up, turn the wheels, go over some gravel etc to get the lights to turn solid. If they don't then there may be a problem. Now, SOME cruisers have a third lock in the front diff, but not many. If you have that function then essentially ALL of the wheels get locked fully together and you become an invincible super-hero!!!!

Does that get you started. Others will chip in, but it would help if you knew which model you were after. Some don't have ANY of this. It's all electronic and taken care of by a troll who lives in the glove box.

Anyone sucking a rat yet?

Chris

 

[Crispin]

Not much to add to the above but on the 120, 150 (and 200?) locking the centre diff also lets the traction control know you are now in "4x4 mode" and the computer behaves differently. This is very evident on snow (and endless fun switching between the two ) and seeing how it works.

If you wanting to test all this on the test drive, a simple "push the button, the appropriate light will flash and go solid, push button again and it will go out" test is fine. That means that that locker is good. if it remains flashing, drive in a slow arc and it should go solid.

Check you can change between H and L on the transfer case and you still have drive (is there a chance you will not? )

As Chris said - update your profile so answers are more fitting..

 

[MrPaul]

You guys are great , all I need to know and I appreciate your time spent. If I could buy you's a pint I would

The Landcruiser owners online link is really the business for newbie information.

 

[piers_finlayson]

And on my 80 the HL lever was _really_ stiff when I bought it. One of the issues was it will only move when the main auto box is in Neutral - which I didn't realise for quite a while!

 

[MrPaul]

I take it that when changing from hi to lo you have to be stationary and in neutral for both manual and auto?

 

[Chris]

Yes. Pretty much. It takes you through neutral on the middle diff so you'd lose drive anyway. On the auto you need to shift into N but on the manual you can just dip the clutch obviously.

Chris