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Hi Guys
If the center diff locks automatically when in low why do we have a center
diff switch on the dash. Is it to lock the center diff while in high.
cheers
john
92HDJ 80 1HDt rep Of ireland
 
Hi John,
Yes and also to disable the centre diff lock in low although you will need to
modify the electrics to make this happen - take a look at the tech pages on
the SleeOffRoad.com site for more info.
Also look on the LCool.org tech pages for info on another approach.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
John
| Hi Guys
| If the center diff locks automatically when in low why do we
| have a center diff switch on the dash. Is it to lock the
| center diff while in high.
| cheers
| john
Most people who fit the dashboard switch disable (one way or another)
the switch that engages the centre diff when in low range.
That way you, rather than Mr Toyoda, choose when to lock your diff.
For example in my case I wanted to be able to do hill-starts on tarmac
with a heavy trailer, requiring low range, and I found that once the
centre diff lock was engaged it wound up the transmission and scrubbed
the tyres, and was also reluctant to disengage.
In addition, selecting the centre diff-lock disables the ABS. You might
want to do this (even in high range) when driving on loose pebbles or
snow, as ABS is a real nuisance in those conditions.
Christopher Bell
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Thanks Julian and Christopher
The reason im asking is I was cleaning the dash and while doing this pressed
the center diff switch and then later when i started the engine and moved
off , the cruiser felt different.
It took a while for it to disengage and was a bit stubburn. Then I
remembered some post from somewhere about the center diff locking in low
automatically.
But mine was not in low in was in high and yet it still locked, so does that
mean I can lock as Christopher said when i want in low or high or have I got
it wrong.
cheers
john92HDJ 80 1HDT
 
John
| The reason im asking is I was cleaning the dash and while
| doing this pressed the center diff switch and then later when
| i started the engine and moved off , the cruiser felt different.
| It took a while for it to disengage and was a bit stubburn.
| Then I remembered some post from somewhere about the center
| diff locking in low automatically.
| But mine was not in low in was in high and yet it still
| locked, so does that mean I can lock as Christopher said when
| i want in low or high or have I got it wrong.
You can lock it whenever you like in high range, and if you do this on
tarmac it will indeed feel a bit different - in particular it will be a
bit more reluctant to go round corners as the tyres will have to scrub a
bit.
Also once you've wound up the transmission it will, as you have found,
be reluctant to disengage because of the load on the diff lock. The
easiest way to unwind it is to go backwards, and wiggling the steering
from side to side usually helps too.
By the way you will be horrifying Julian. Cleaning? A Land Cruiser?
What is the world coming to!
CB
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Hi Christopher
as long as I know you have 96mod. and there is no switch for that
diff.lock on the dash.Did you modified it?
Cheers
Lubo
96HDJ80
On Mar 20, 2006, at 4:46 PM, Christopher Bell wrote:
 
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Hi Christopher
Ok so if that is the case what is all this about electrics to be able to do
this locking in high.
You are right about the difference, I knew straight away with the steering
and the slow responce.
So whatis the difference between locking it in low or locking it in high. Is
it you can travel quicker in high and the gears will change where as in low
it is limitied speed and gear wise.
I know about the cleaning sure didn't a certain man, no names mentioned look
under my front wheel arch when I was over in the UK around the south of
wales last year and looked horrified to find no mud at all. I aim to please
him this year at Salisbury by finding loads of mud holes to wollow in and
maybe the cruiser too.
cheers
john
92HDJ 80 1HDT
snip
You can lock it whenever you like in high range,
By the way you will be horrifying Julian. Cleaning? A Land Cruiser?
What is the world coming to!
CB
 
Lubo
|
| Hi Christopher
| as long as I know you have 96mod. and there is no switch for
| that diff.lock on the dash.Did you modified it?
| Cheers
| Lubo
You have to buy the switch from a Toyota dealer (about =A350), then fit it to the dash. The wiring is already there behind the dash, at the top right (on my right hand drive model) behind a blank switch position. You pull a plug off the connector, fit it to the switch, and that's that.
It is a really easy fix - takes about 5 minutes, of which 4 minutes is unscrewing and refitting the dash panel. See http://www.lcool.org/technical/80_series/80_series_technical.html (you want link "Centre Diff lock, manual control in High range", but the other links are worth reading too.)
I have a manual gearbox, so I just disconnected and taped up the switch on the transfer case to stop it being engaged in low range, so now I have exclusively manual control of the centre diff-lock. It's described in those pages, but just one hint: make sure the exhaust is cold before you start poking around under there!
If you have an auto box you can still disconnect the switch on the transfer case, but apparently the ECU gets in a bit of a muddle with gear-change speeds, and you are better off doing a "pin 7 mod". You'll have to ask someone with an auto box what it is all about!
Christopher Bell
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John
| Ok so if that is the case what is all this about electrics to
| be able to do this locking in high.
The diff-lock is always switched on and off electrically. The fact that
it comes on when you select low range is because moving the high/low
gear lever moves a shaft which presses a switch attached to the transfer
case - so engagement is still controlled electrically. The switch on
the transfer case and that you've added on the dash are in parallel, and
both do exactly the same thing.
| You are right about the difference, I knew straight away with
| the steering and the slow responce.
| So whatis the difference between locking it in low or locking
| it in high. Is it you can travel quicker in high and the
| gears will change where as in low it is limitied speed and gear wise.
No difference at all: locked is locked, and unlocked is unlocked
regardless of whether you are in High, Low or Neutral. The assumption
is that if you are in high range you will be going quickly on a good
surface and won't need the centre diff lock, whereas if you are in low
range you will be on a poor surface and will need it.
The first is not unreasonable, but the second definitely isn't. Anyone
who manoeuvres heavy trailers will use low range, and on a good surface
this winds up the transmission horribly if the centre diff-lock is
engaged.
Personally I would never engage it on a good surface, in either high or
low range, as it would only reduce the effectiveness of the steering,
put excess load on the transmission and wear out the tyres!
| I know about the cleaning sure didn't a certain man, no names
| mentioned look under my front wheel arch when I was over in
| the UK around the south of wales last year and looked
| horrified to find no mud at all. I aim to please him this
| year at Salisbury by finding loads of mud holes to wollow in
| and maybe the cruiser too.
Maybe Julian won't cancel your list membership after all then!
CB
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Hi Christopher
This is a good tutorial.
Ok so once the center diff is locked its locked regardless of whether its by
the switch or by the position of it being in low gear.
Is the steering the only thing that is effected by the center diff locked.
So will anything happen if you put it in low and press the diff switch or is
locked, locked.
So one could drive in high at speed with center diff locked if you were mad
enough to do it of course.
So center diff locked in low is better than center diif locket in high for a
few reasons, so why have the option of center diff locked in high if its no
good really.
cheers
john 92HDJ 80 1HDT
 
John
| So will anything happen if you put it in low and press the
| diff switch or is locked, locked.
If it is already locked by virtue of selecting low range then no,
pressing the dash switch will have no extra effect.
| So one could drive in high at speed with center diff locked
| if you were mad enough to do it of course.
| So center diff locked in low is better than center diif
| locket in high for a few reasons, so why have the option of
| center diff locked in high if its no good really.
The dash switch isn't really there to lock it in high. Most people who
fit it then disconnect the switch on the transfer case, so that engaging
low range no longer locks the centre diff. Therefore the purpose of the
dashboard switch becomes simply "driver control of centre diff lock,
independent of what the transmission is doing".
Really, to complete your mod, you need to stop the centre diff-lock
engaging when you select low range. I know you've got an auto box, so
I'm going to let someone else who also has one to explain what to do.
CB
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Hi Christopher
This dash switch has been there all along I didn't install it, just had a
few questions regarding the use of it when centre diff already locks in low
already, what is the use of it. seems to duplicate the same proceedure does
it not.
cheers
john 92HDJ 80 1HDT
 
John
| This dash switch has been there all along I didn't install
| it, just had a few questions regarding the use of it when
| centre diff already locks in low already, what is the use of
| it. seems to duplicate the same proceedure does it not.
| cheers
Previous owner must have fitted it then.
Or do you not have ABS? If you don't then I think it is probably
original Toyota fit, but in that case I wouldn't expect engaging low
range to lock the centre diff.
Anyone else got any views?
CB

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Hi Christopher
No ABS, either on the cruisers or me im afraid.
cheers
john
 
Hi Christopher,
They were fitted as standard on early 80s before ABS came along.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
Hi John,
You lock the centre diff to increase traction.
If you are in extremely slippery conditions you can lead to a situation where
all the power is diverted to just one wheel causing it to spin.
If you lock the centre diff you are ensuring that power is fed equally to the
front and rear axles so worse case scenario you end up with two wheels
spinning.
You then lock your rear diff which results in three wheels spinning.
And then if you get that you lock the front diff resulting in the worse case
scenario of all four wheels spinning.
You can replicate the above on extremely slippery fields or icy roads, as I
have over the last month - and if you are towing a vehicle up an icy hill,
fully locked and all wheels spinning it gets very interesting!
There is a good 'Diffs for Dummies' write up that should explain things a bit
better at:
http://www.lcool.org/technical/diffs/diffs.html
Also check out the following links about the Centre Diff Lock mods:
http://www.lcool.org/technical/80_series/centre_diff.html
http://www.lcool.org/technical/80_series/abs.html
http://www.sleeoffroad.com/technical/tz_cdl_pin7mod.htm
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
Hi Julian
Now that has got me asking more questions.
If you have the center diff lock switch on the dash you do not have it
automatically locked while in low range is that right.
It is up to you when of if you want it locked.
Can you lock all the diifs for the entire time you are on a slippery surface
without harm to the diffs or do you need to give them a break from time to
time.
So once on slippy stuff your steering should be fine.
What gear will low keep you in.
Will the power going to one wheel while the three others are spinning
transfere to the others as the traction gets better under each.
If you engage the center diff, then the rear, then the front, do you have to
disengage all the diffs in the reverse of the way you engaged them.
If you disengaged the center diff would the rear and front diffs also
disengage.
cheers
John 92HDJ 80 1HDT
 
John,
Let me take this up as I probably have more time than Julian.
Your centre diff will still lock in low automatically unless you
have dissabled it. The pages Julian pointed to give a write up on
this, I think.
Yes you can lock all the diffs if you are on a slippery surface,
you should get them out when you come off, the axle diffs as soon as.
They do not need a break, you are on a dodgy surface, you are not
going to hammer it.
Low does not keep you in any gear, there are virtual set of lower
gears that the vehicle uses, you still have four forward and one
reverse.
No, traction goes to the wheel that is spinning. When you lock
the diff on that axle it stops the spinning as it locks the wheels
together.
The diffs are not quite independant. The toyota switch will not
let you take out the rear axle without taking out the front first. The
centre diff is independant of the other two and should be engaged
first and taken out last, it is OK to leave the centre in all the time
you are on a slippery surface, weather you have traction or not.
Regards, Clive.
 
Hi Clive
Thanks for that, very clear now my mind is at ease I think for this anyway.
In the Diffs for dummies it says on page 5 at the top it says,
( when low range is selected (or) the centre Diff lock switch is depressed
an electrictial signal is sent to the centre diff lock and the centre diff
locks).
Does the OR in the above mean that there is a choice or do you have to, as
you say disable it before you have this choice.
When the engine transferes the power to the driveof the axles where is this
point of transfere, is it at the transfere case or at the front axle and
then to the other axle. Im asking because the engine is up front so closest
to the front of the drive to the axles.
cheers
john
 
Hi John,
The default behaviour is for the centre diff to lock up when put into low
range, regardless of whether you have the CDL switch installed. To override
this behaviour you need to either carry out the Pin 7 mod or unplug the main
control wiring from the transfer case - both of these techniques are described
in the last three links in my last email.
Only when you do the mod mentioned above.
It is best to lock them all until you no longer need them. The biggest strain
when locked up is on the CV joints when you turn the steering wheel,
particularly if they are slightly worn.
If you have no grip and are fully locked up and then suddenly get grip it can
lead to a cv joint or halfshaft snapping, but this is very rare although
exasperated if the components are worn.
Yes when fully locked up, although the steering is very stiff.
It's down to your auto box - you still get the three gears in low as you do in
high although the changing points are different (the gearbox tends to hang onto
the gears, only changing when the revs get higher).
If you do the Pin 7 mod you will get complete control over the used of the
centre diff lock, but retain the standard low range change pattern for the
gearbox. If you remove the connector from the tranfer case you get the full
control over the CDL and allso the benefit of the same gear changing pattern in
low range as you have in high range.
Personally I have gone down the Pin 7 mod route, but next time around (or when
I get the chance to change it I would rather go the route of removing the
connector on the transfer case so that I have more useful changing pattern for
the gears.
The power is going to the wheels that are spinning - have a good read of the
Diffs for Dummmies page to fully understand this.
No, although the front and read diffs will only engage if the CDL is locked and
you are restricted by the rotary control of the front and rear diff locks so
the rear engages before the front and in reverse the front is disengaged before
rear.
Eventually, yes. Whilst the actuators will disengage, the actual locks won't
actually disengage until you releive the pressure on them, usually from turning
a corner, or stopping, etc.
I hope that helps a bit ;-)
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
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