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no lockers

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Jul 23, 2022
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read the info about my land cruiser and although when in four wheel drive low the center transfer locks however the truck dosen't have the center lock switch, I'm looking to triple lock it at some point but not sure what the center lock option does and the benifit of having it.
 
Power always goes to all four wheels , when you select low range it locks the centre to increase grip with a more even distribution of power .

Few came with the option to use low range without locking the centre but its an easy mod to add giving you the button .

Thats my questionable understanding of it anyway , it had already been done on my 80 when i bought it .
 
Yes. The mod Shayne speaks of is to add the switch and optionally remove a wire on the transfer case to only enable locking with the button. The button means lockable in 4 high and the wire mod means it’s optional in 4 low giving low range option on tarmac.
Are you sure it has no locker in the rear diff? It could have a Limited Slip Diff as many did. These work well and can be seen by a ‘LSD’ sticker by the oil filler on the rear axle and a code on the vin plate. Something like K295 with the 5 being LSD to rear. There’s an explanation of codes somewhere on here if you do a search.
 
thanks for all the great info, I'll check it out and see. sounds like the mod would be good in sand but not a game changer.
 
It absolutely is a game changer...when as you say you intend to add axle locks.
But I want to clarify something mentioned above. A single locker - center diff or otherwise - simply splits input power 50% between two outputs. Where both axles are open (no locker), a center diff lock only ensures that both axles receive (presumably) 50% of the motive force (engine torque).
But after that, the open axles really only send power to just one wheel. You're only 2wd.
Put another way, to have axle locks and no center lock, all you'll ever have under power for certain is a single locked axle. (still only 2wd)
The center lock is a necessary part of being 3xl. Now or later.

Now, the button...is part of the overall mod to have control over the center lock in low and high range.
You need the button and the 'pin 7' mod to complete the install.
 
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I would have thought it "compulsory" to have 4wd in low as there is high torque which might damage the driveline. I assume that is why there is a switch on the transfer.
 
I would have thought it "compulsory" to have 4wd in low as there is high torque which might damage the driveline. I assume that is why there is a switch on the transfer.
Well, low certainly increases torque to the axles.
But "powered 4wd" is only achieved with 3 locks - 1 center and 2 axles.
A switch on the center only ensures power to each axle (2wd)
Not each wheel (4wd)
It could be said that today's AWD is yesterdays "4WD" in the sense that - in my '80s/'90s case anyway - vehicles in the US marketed as 4wd had no axle locks. Shifting to low range locked the center w/o a button, but still only 2wd in reality.
And always not the wheel with traction, as they do. lol
 
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next step after all the great information will be to get the switch and find out how to do the pin 7 mod. thanks everyone for the help I'm so glad to have found this great forum and look forward to meeting some of you at upcoming events. thanks again
 
There’s a thread on the pin 7 mod somewhere on here.
Frank is right, and it’s something Toyota state iirc, that when in 4 low the centre Diff is locked to send and distribute power evenly to the 4 wheels. However the pin 7 mod is to allow 4 low on solid non slippy surfaces like tarmac, to allow 4 low without ‘winding up’ the drive line when cornering. This could be used for road towing something heavy up hill for example.
 
All the above in a nutshell, your 4WD is only 4WD when all four wheels have traction, without locks/LSD/VC lose traction with any wheel and the vehicle stops moving.

Regards

Dave
 
However the pin 7 mod is to allow 4 low on solid non slippy surfaces like tarmac, to allow 4 low without ‘winding up’ the drive line when cornering. This could be used for road towing something heavy up hill for example.
If I may respectfully disagree, and too perhaps I misunderstand your previous...
...my experience is that the pin 7 mod (and button) allows full, manual control over the center lock, at all times, in low or high range.
W/o the mod, and regardless of the button, the center only locks when the t-case is shifted to low range.

I don't believe Toyota ever intended for the center to lock in high range as there is no 80 model from the factory that allows this function. And to do so requires a full understanding of what is going on mechanically or one risks damage to the drive line, person, or both.

I think the main reason it even became a thing is that some folk wanted to lock the front axle w/o locking the rear axle. Which I do not recommend unless you've fortified the front 3rd.
But if you wanted you'd still need the center lock button, independant electric switches to each axle lock (OEM locks), plus a couple other wiring mods. (or aftermarket locks)
 
I don't believe Toyota ever intended for the center to lock in high range as there is no 80 model from the factory that allows this function. And to do so requires a full understanding of what is going on mechanically or one risks damage to the drive line, person, or both.
Mine has the switch…from factory, allowing locking in high range if desired.

With the factory front and rear lockers, the selector rotary switch engages the rear Diff lock first and won’t allow the front to become locked until the rear is confirmed locked by it’s switches. Neither are allowed until the centre Diff is fully locked.
 
Maybe I've got the wrong end of the stick here but I thought all the "pin7" mod does is change the shift pattern of the auto box when in low range. The shift pattern of the auto is different in high and low ranges. The mod has nothing to do with actually locking the CD in the transfer case which is done by a switch on the case itself. It's this switch which is unplugged and "replaced" with the dash switch, thereby removing the default behaviour of locking the CD every time low range is selected.
 
Mine has the switch…from factory, allowing locking in high range if desired.

With the factory front and rear lockers, the selector rotary switch engages the rear Diff lock first and won’t allow the front to become locked until the rear is confirmed locked by it’s switches. Neither are allowed until the centre Diff is fully locked.
Could a PO have performed the pin7 mod to your rig?
In the US, the factory center diff switch originally only allowed an unlocked center in low.
If you are getting a response in high, it suggests the mod has been performed.

But I'm also willing to accept that different markets received functional differences in how that button works.
:orcs-cheers:
 
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Maybe I've got the wrong end of the stick here but I thought all the "pin7" mod does is change the shift pattern of the auto box when in low range. The shift pattern of the auto is different in high and low ranges. The mod has nothing to do with actually locking the CD in the transfer case which is done by a switch on the case itself. It's this switch which is unplugged and "replaced" with the dash switch, thereby removing the default behaviour of locking the CD every time low range is selected.
Agreed there is a different shift pattern between low and high. But using the button in my rig makes no difference in that regard.
How does it work in yours?
I can lock the CD at will with the push of the button, low or high.
If I attempt to engage the axle locks w/o hitting the CD button, the CD locks automatically to allow the axles to lock.
And for the record my trucks PO had all this done but he failed to mention it at purchase.
I only discovered it after learning on my own what I could do with the button and finding it 'out of spec'. lol
 
Taking one step back here.
The 80 came in many different configurations when it comes to 4wd, depending on market and choice of options.
Some did not have permanent 4wd and had mechanical selection of either 2H, 4H or 4L. A transfer box like that has no differential: There is no CDL switch, and no possibility for one either. When in 4wd, the front and rear are always locked to eachother, meaning that 4wd is for off-tarmac use only. This is what it sounds like you have, Jim.
Vehicles with that type of transfer came with either only LSD in the rear, RDL, or both RDL and FDL.
Then you have all the versions with a central differential and an electric actuator for locking it, which is what has been discussed here.
 
Agreed there is a different shift pattern between low and high. But using the button in my rig makes no difference in that regard.
How does it work in yours?
I have a manual so there's no such jiggery pokery involved.
 
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