Center Diff Locked and can't unlock! Transmission windup?? HELP

[anna888]

Ok so I don't know much at all about cars so be nice!

We are currently trying to sell our Manual 1998 Prado GXL, a guy came round and took it for a test drive and drove on bitumen in LL, ever since the centre diff lock has been stuck on and when you turn a tight corner left wheels are chirping and spinning.
I have googled whats going on and it sounds like transmission windup? Transmission windup would be the cause for the diff lock to be stuck on?

If this makes any sense to anyone, HOW DO I FIX IT?? I have read you can jack the front wheels up?
I just want to get it back into the right gear and get diff lock of so i can take it to the mechanic

 

[Shayne]

Get it on soft or loose ground a beach or gravel , even grass and just keep doing laps while trying to move in and out of LL . Transmission wind up is a sort of catch all phrase for damage that can be done by driving on a firm good grip surface with locked diffs .

Changing the transfer box oil might be a good idea .

 

[Chris]

If Shayne's tricks don't work, stick it in reverse and drive backwards in a slalom style left to right. That should really do it. You do really need to make sure that the lever is all the way back into H4. The centre lock can be tricky to disengage if it's not been used much, but do try to avoid very sharp turns. These are strongly built boxes and you're unlikely to break it, but it's not very kind. It should only need to hit the alignment spot to unlock. The CD is a mechanical lock, not electric so there's no wiring nonsense to have to worry about. Backwards should be better really than trying to dive forwards any further.

Not quite sure how an oil change would be necessary .. Unless of course it's due

 

[anna888]

If Shayne's tricks don't work, stick it in reverse and drive backwards in a slalom style left to right. That should really do it. You do really need to make sure that the lever is all the way back into H4. The centre lock can be tricky to disengage if it's not been used much, but do try to avoid very sharp turns. These are strongly built boxes and you're unlikely to break it, but it's not very kind. It should only need to hit the alignment spot to unlock. The CD is a mechanical lock, not electric so there's no wiring nonsense to have to worry about. Backwards should be better really than trying to dive forwards any further.

Not quite sure how an oil change would be necessary .. Unless of course it's due

Thanks for your replies. I live in town and am a fair way from any paddocks, beaches or gravel! I would also have to drive it somewhere to try reversing it too.
Would driving it as is do major damage?

When reversing should I have gear stick in H4 to start?

Have you ever heard of fixing the problem by jacking up front tyres?

Thankyou so much

 

[Shayne]

Back and forth 10ft should move it eventually , imagine the gear stick pushes a metal pin into a hole and pulls it out again but the pins gone rusty . It will only come out when its lined up properly and because its rusty its reluctant to come out anyway .

Baby it and worry it until it moves . Is the oil likely to be good and full ? topping it up or changing it is something you can do yourself if you have a spanner . Jump to 3 mins

 

[Chris]

Driving it on tar is more likely to ruin your tyres to be fair. There are those who will go weeping and wailing about damage to the transfer box if you drive more than a millimetre with it locked but honestly they just need to pull up their big boy pants.

Yes the lever needs to be in H4, I did say that. You're not going to unlock it with the lever in the locked position.

You can stick it in N for neutral and jack it up so you can wiggle a wheel, yes. But I'd be more inclined to wiggle a rear wheel. They person who drove it didn't also turn the dial to lock the rear locker did they? If you don't have that, then you have a rear limited slip diff. Not all countries got the rear locker.

But as Shayne says, backing up a few feet should do this. I'd be staggered if you had to go somewhere special to reverse a car anywhere on the planet.

 

[anna888]

Thankyou thankyou thankyou its fixed! Reversed up the street in zig zag and clunk its back!!!! THANKYOU

 

[Shayne]

The next potential buyer will probably put it back in again lol

Its not broke just lazy through lack of use so you might want to put it in and out a few times so it doesn't fail and put the next buyer off

 

[anna888]

Ok will do Thanks again you've made my day!

 

[StarCruiser]

Glad it's sorted Anna and welcome to the forum. As you may have noticed we're a friendly bunch on here. Although you're selling your Cruiser, I hope you'll stick around. Might be a good idea to do a description in the classifieds section on the forum. Who knows, you might get it sold to a forum member especially if you give your rough location. Maybe you'll go for another cruiser? Err, why are you selling may I ask?
Oh, BTW for someone who says they don't know much about cars, you did good gal! And joining up on here will give you lots of help and advice.
Best wishes
Richard

 

[clivehorridge]

How is it I wonder, that this thread had only just appeared on my iPad, when I've been on here quite a bit yesterday and today?

It's been running since late Saturday evening, and only just appeared at 11:11pm on Monday? Very odd.

Anyway, good to see a happy ending and welcome to the forum Anna, by the way

And the next question must be why are you selling?

(Just sayin')

 

[Chris]

Clive, have you tried backing it up ......

 

[clivehorridge]

Clive, have you tried backing it up ......

You mean reversing Chris? Or is this another sort of wind-up...

 

[Chris]

I couldn't help myself there bud.

 

[clivehorridge]

I couldn't help myself there bud.

Forgiven.

That's what I'm here for Chris, so it seems, and it's my pleasure...

 

[Jack VZJ90]

Ok so I don't know much at all about cars so be nice!

We are currently trying to sell our Manual 1998 Prado GXL, a guy came round and took it for a test drive and drove on bitumen in LL, ever since the centre diff lock has been stuck on and when you turn a tight corner left wheels are chirping and spinning.
I have googled whats going on and it sounds like transmission windup? Transmission windup would be the cause for the diff lock to be stuck on?

If this makes any sense to anyone, HOW DO I FIX IT?? I have read you can jack the front wheels up?
I just want to get it back into the right gear and get diff lock of so i can take it to the mechanic

There's an easy way to do this.
1) reverse and make some speed.
2) put your automatic transmission in neutral. / or put you gearbox in neutral and press coupling pedal.
3) put some force on your stick from transfer case to shift it to N and H, while car still slow reversing.

central difflock comes loose.

Make no sense to turn the front wheels, because the LL (low-lock) is in you transfercase, and not in your front differential.

 

[Dave2000]

There's an easy way to do this.
1) reverse and make some speed.
2) put your automatic transmission in neutral. / or put you gearbox in neutral and press coupling pedal.
3) put some force on your stick from transfer case to shift it to N and H, while car still slow reversing.

central difflock comes loose.

Make no sense to turn the front wheels, because the LL (low-lock) is in you transfercase, and not in your front differential.

I have no experience with this particular model but do not agree about not turning the steering. True the problem is in the centre differential but, with the steering turned the front and rear wheels try to travel at different speeds, thus loading and unloading the lock enabling it to come free.

Regards

Dave

 

[Towpack]

I have no experience with this particular model but do not agree about not turning the steering. True the problem is in the centre differential but, with the steering turned the front and rear wheels try to travel at different speeds, thus loading and unloading the lock enabling it to come free.

Regards

Dave

 

[Jack VZJ90]

I have no experience with this particular model but do not agree about not turning the steering. True the problem is in the centre differential but, with the steering turned the front and rear wheels try to travel at different speeds, thus loading and unloading the lock enabling it to come free.

Regards

Dave

Hi Dave,
A landcruiser J9 is permanently 4 wheel driven.
Cost a little more fuel, but drives great under all conditions, and has quite equal tyre wear at front and back.

When putting your transfercase in LL the front and rear shaft grab each other.(central-diff-lock)
It's my experience that the front end always pulls harder then the back, mostlikely because you have more weight on the back axle (wheels) when accelerating. That creates an extra grab in the diff-lock, causing unlocking problem.
If you reverse, you push your weight on te front wheels, so your back wheels run just a little faster. (spinning) and that's when your lock comes of, especially when you, while reversing, put your gearbox or ATM to neutral. The shaft from the gearbox doesn't connect with your transfer case, so one problem less to synchronize.

With a front diff and rear diff lock, steering sure helps
When you make a left turn, your left wheel makes a shorter, and your right wheel a longer loop.
The are trying to compensate each other in your front and back differential and unlock the diff.

Anyway as long as you can unlock it in your own comfortable way it'll do the trick.

 

[Dave2000]

@jack VZ90 said:

Hi Dave,
A landcruiser J9 is permanently 4 wheel driven.
Cost a little more fuel, but drives great under all conditions, and has quite equal tyre wear at front and back.

Dave 2000 replies in Blue:

The 80 is also permanent 4WD but only when all four wheels have traction, I guess just like the 90, although there is a caveat here which I will come back to.

When putting your transfercase in LL the front and rear shaft grab each other.(central-diff-lock)

Again the same as the 80.

It's my experience that the front end always pulls harder then the back, mostlikely because you have more weight on the back axle (wheels) when accelerating. That creates an extra grab in the diff-lock, causing unlocking problem.

I do not agree, the load on the diff lock is varied, on a grippy surface the load is the same, if the diff lock is being used is due to poor traction then the load varies dependent on available traction. Poor traction equals less weight transfer to either end of the vehicle again dependent on traction however, the rear does not have the weight of an engine permanently on top of it.

If you reverse, you push your weight on to front wheels, so your back wheels run just a little faster. (spinning) and that's when your lock comes of,

I agree if you put your foot down in reverse and get one wheel to spin you have altered the load on the centre lock which should release it, which is exactly what happens if you reverse in a figure eight, this because the front wheels are scribing a greater arc than the rear.

When you make a left turn, your left wheel makes a shorter, and your right wheel a longer loop.

Agree, in exactly the same way as the front and rear wheels in fact, it could be argued there is more slack in the drivetrain front axle to rear axle (diffs/propshafts/gearbox internals/transfer internals), than what there is across a single axle, thus perhaps making it easier to get the load off the lock?

Something else I am not comfortable with, that is advising a non knowledgeable contributor to move the shift lever whilst reversing (at speed) whilst unlikely a problem with a manual, moving an auto from reverse to neutral opens the possibility of moving into D i.e selecting a forward set of planatery gears going backwards, could that cause damage?

Reversing in a figure 8 is a tried and trusted solution for all but the most stubborn centre diff locks IME.

The caveat about all four wheels need traction is not entirely true for some 80's that are fitted with a VC in the transfer.

Regards

Dave