Lock Differential Button: When to Press it? (1 Viewer)

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Perhaps a too simple question. I know that you press the lock differential button on the dash in my 2004 LC (just bought it used) -- when you want to lock the differential. I've read the instructions - and it just states to press the button to lock the differential. My question has to do with - when can you press it? While in motion? While in drive but stopped? Or do you have to be in park? I would be using it to drive on snow covered roads. Thanks - Mike
 
You can press the CDL at any time. Moving or not. There have many of us to accidentally hit the button with our knee at 75 mph. No issues.

However, you don’t want to engage the CDL and then turn wheels on hard surfaces. Pavement NO, sand or soft dirt with low traction YES.
 
I've found it's a little smoother when travelling straight, not under load and not in the middle of turn. Mine's not always instantaneous either. May take a bit before it finally engages although I don't use it often.
 
It should be noted that you just want to make sure you don't engage it while you have wheel spin. Not likely but if you find yourself slipping and sliding up a hill just make sure you stop the wheel spin before hitting the button.

Personally I like to have the revs at idle and have the vehicle rolling along to engage and disengage , seems to be the smoothest for my rig but everyone's technique will vary.
 
^^^^^
 
It's probably worth noting (perhaps for other new owners rather than yourself) that locking the central diff only gives you true drive to one front and one rear wheel.

I find when climbing wet grass without CDL the right front wheel is very likely to lose traction first. Without axle diff lock(s) or limited slip axle diff(s) only the right front wheel gets any 'drive' in that scenario..... and I get stuck.

Engaging the CDL will send ~50% of the 'drive' to a rear wheel in addition to a front wheel. which make a vast difference.

It's little wonder triple lockable Land Cruisers are so sought after.
 
It's probably worth noting (perhaps for other new owners rather than yourself) that locking the central diff only gives you true drive to one front and one rear wheel.

I find when climbing wet grass without CDL the right front wheel is very likely to lose traction first. Without axle diff lock(s) or limited slip axle diff(s) only the right front wheel gets any 'drive' in that scenario..... and I get stuck.

Engaging the CDL will send ~50% of the 'drive' to a rear wheel in addition to a front wheel. which make a vast difference.

It's little wonder triple lockable Land Cruisers are so sought after.

For sake of accuracy, the Center Diff Lock when engaged simply causes the Transfer Case to send power equally to the front and rear driveshafts. They also turn at the same speed when the T-case is locked.

As for which tire on any given axle is driven....is dependent on whether or not you have an open differential or traction aiding devices (lockers, limited slip) and in some cases conditions that influence torque bias.

But yes, engaging the CDL on a vehicle with open diffs....insures you have equal power to at least two driving wheels as you alluded to. 👍
 
For sake of accuracy, the Center Diff Lock when engaged simply causes the Transfer Case to send power equally to the front and rear driveshafts. They also turn at the same speed when the T-case is locked.

As for which tire on any given axle is driven....is dependent on whether or not you have an open differential or traction aiding devices (lockers, limited slip) and in some cases conditions that influence torque bias.

But yes, engaging the CDL on a vehicle with open diffs....insures you have equal power to at least two driving wheels as you alluded to. 👍
Thank you for your answer - and again, thanks to all who have answered my query! Mike
 
Welcome to the Forum Mike. Congratulations on your purchase. We hope to see you here participating often.
 
Welcome to the Forum Mike. Congratulations on your purchase. We hope to see you here participating often.
Thank you. My wife and I have had an FJ 40, FJ 62, and we think it was (neither of us can recall the year) a series 100. All of those were prior to 2007. We just sold 2 cars to buy a used series 100. But I could not figure out the details on using the center diff button. I'm glad that the forum is here. Mike
 
It's probably worth noting (perhaps for other new owners rather than yourself) that locking the central diff only gives you true drive to one front and one rear wheel.

I find when climbing wet grass without CDL the right front wheel is very likely to lose traction first. Without axle diff lock(s) or limited slip axle diff(s) only the right front wheel gets any 'drive' in that scenario..... and I get stuck.

Engaging the CDL will send ~50% of the 'drive' to a rear wheel in addition to a front wheel. which make a vast difference.

It's little wonder triple lockable Land Cruisers are so sought after.
This description is correct for 98-99s (theoretically you could have a wheel spinning on each axle and no traction). For 2000+ ATRAC will sense wheel spin and apply individual braking to transfer power to the wheels with traction.
 
This description is correct for 98-99s (theoretically you could have a wheel spinning on each axle and no traction). For 2000+ ATRAC will sense wheel spin and apply individual braking to transfer power to the wheels with traction.

Correct. It is also possible to have NO traction (read not enough to move the vehicle) with either set up due to conditions.

I suppose the ultimate set up would be ATRAC with lockers in both front and rear diffs. Next, a triple locked set up (98-99). Next in line...a locker in at least one diff. Then a limited slip in at least one diff and lastly open diffs.

Then we have to venture off into which set up is the best for what conditions which is a whole 'nother discussion. Isn't off-roading fun? ;)
 
This description is correct for 98-99s (theoretically you could have a wheel spinning on each axle and no traction). For 2000+ ATRAC will sense wheel spin and apply individual braking to transfer power to the wheels with traction.
Excellent point. I hadn't considered electromechanical traction aids in my post which was an error on my part, so thank you for pointing it out.

I have three 4x4s in my work fleet but none of them are newer than 1999 so I forget that there are more modern alternatives (that TBH I don't want as there's no one on this Island who can fix much electronic. Simple and mechanical works best for my way of life).

My '99 LC is in low ratio three or four times a week. We go places on a weekly basis that few others living in cities would go in years. It's just the way we have to live, work and eat here... and I love it.
 
Simple and mechanical works best for my way of life).

My '99 LC is in low ratio three or four times a week. We go places on a weekly basis that few others living in cities would go in years. It's just the way we have to live, work and eat here... and I love it.

Sounds awesome, pretty jealous.
 
Excellent point. I hadn't considered electromechanical traction aids in my post which was an error on my part, so thank you for pointing it out.

I have three 4x4s in my work fleet but none of them are newer than 1999 so I forget that there are more modern alternatives (that TBH I don't want as there's no one on this Island who can fix much electronic. Simple and mechanical works best for my way of life).

My '99 LC is in low ratio three or four times a week. We go places on a weekly basis that few others living in cities would go in years. It's just the way we have to live, work and eat here... and I love it

How about a few pics of these awesome places you speak of and, of course, your land cruiser.
 

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