Rear Locker in 2 and 4 high

Okay. Please explain why driving on pavement in 4H with the diffs both open would be worse (cause more damage) than having the rear end locked together on pavement. I’m not an expert on this but would love to hear why. I’ve put over 200k on my last Taco and used 4H extensively on the pavement because we have so much patches of ice on the roads where we live in the winter that I never take it out of 4h when there’s any kind of ice on the roads especially when my wife is driving it. Always have done this with all my 4x4s and never once have had any problems with any of them. In fact a lot of times I forgot I even left it in 4h until I start it the next day as you really can’t feel too much of a difference. But when driving in my Prerunner locked or my 2wd with a Detroit locker locked up on drive pavement you can totally feel it as the Prerunner didn’t handle the same especially when cornering.

So if you can explain why for my own knowledge I would appreciate it.

 

You are obviously wrong, I have had a 2wd with a rear locker, which is why I'm never going to own another one....

 

I don’t follow. Which rig did you own with a rear locker and why wouldn’t you own another?

 

Nothing wrong with driving a vehicle on the street with a auto locking diff such as a Detroit locker or clutch style limited slip posi .I've driven both on the street for many years with no issues

I've even driven vehicles on the street with spools with no issues !!!! , my Camaro is running a Ford 9" with a spool and 35 spline axles and Drag radials on the street . Again no scary ill handling , drives very nice

 

Already did, see post #21.

Rear locked binds the rear axle which just isn't typically concerning.

4H with open diffs introduces bind at all driven wheels which includes the front and that is more of a concern.

 

I agree with you with those examples. But we were originally talking about the effect on a Toyota electronic rear locker.

 

Only two wheels are guaranteed to be driven when in 4H just like with the rear end locked in 2wd. I kinda of find it funny when people think their 4wd vehicles are always driving 4 wheels. Just like a 2wd. Only one wheels is guaranteed to be spinning at any given time.

Anyway, if having the rear end locked doesn’t effect anything then why do Toyota’s rear locker and just about all other electronic rear lockers from other manufacturers automatically turn off after about 10mph and can’t be used at any given time? Seems like if there was any benefit to having it locked and not causing any unnecessary wear and tear, then they wouldn’t all automatically unlock and you could manually do it. I’ve have had many factory electronic lockers from different manufacturers and they all turned off after a given MPH that wasn’t very high. The only exception was to a Audi Quattro and a Audi 4000CS Quattro that I’ve owned. And boy did you know it when you hit a corner going very fast with the rear locked up. Scary!

 

Because to me a 2 wheel drive truck is useless, with no weight in the rear there is no traction

 

Personally I would like to have the ability to activate the rear locker in 2wd because it would allow me back my travel trailer in next to my house up a slight slope covered in gravel which also requires making a sharp right turn with the front wheels of the truck on pavement. Couple all of that with the high reverse gear in the MT and it’s a bit of a challenge.

GN you may not be experiencing problems using 4H in icy conditions because the portions of the road which aren’t icy are likely still wet which will allow your wheels to ‘slip’ and not bind-up your Transfer Case. If you did the same thing on dry pavement you would likely cause damage.

 

That was my point exactly!

 

I agree with everybody that says being able to lock the rear up in 2wd can be beneficial taking off in grass or slippery conditions. But it seems like so many people think being able to lock up the rear in 2wd is going to get them through mud, deep snow, and or is almost as beneficial as having a 4x4 in 4h. It’s not even close. Go drive a Prerunner with the optional rear locker and try going through these conditions and report back and tell me how you do. We sold ours just because it couldn’t even get us through snowy condition in the winter where we live. Any 4x4 in 4h will eat up a locked Prerunner (running the same tires of course).

 

Unfortunately you haven't grasped a thing I've said and you don't understand how locked tcases and open differentials work. Locked tcases force front and rear outputs to rotate at the equal speeds and are capable of torque bias up to 100%. Open differentials force left and right outputs to receive equal torque and are capable of varying the speed bias to any ratio such that the average of the two angular velocities matches the angular velocity of the differential carrier. Using this information you can figure out how bind will occur.

Toyota only limits you to the act of engaging the rear elocker to under 5 mph. Once it's engaged it won't turn it off at any speed.

Where did I say a locked rear doesn't affect anything? I clearly stated it binds the rear. So the rear scrubs.

In 4wd you bind at both the front and rear. Therefore the front and rear must scrub.

 

But wouldn’t it just bind one in front and one in the rear in 4h as the others can rotate at different speeds?

 

Personally, I'd just like the option. The reason I got a TRD Off Road was crawl control and the locking diff. It would be nice to not have to go all the way to 4L to engage it when needed. At the very minimum I'd like the option in 4H because chances are I'm probably already in that.

That being said, I do agree with some comments on here. Sometimes you just need it quick and the 4x4 shift takes too long sometimes. My old Canyon was very quick at shifting into 4x4 and what little I've tried with Nissan and Toyota, I can't say it is as quick and even sometimes requires movement of the truck.

 

I second this!

 

Are you running air lockers?

In my experience the factory e-locker is dead reliable whereas the ARB stuff can be finicky and lacks the indicator light when its on/off which are nice features to have.

 

Does arb or tjm even make a locker for a e locker third? Unless you want to swap the axle housing, just run the e locker. If the motor fails, you can take the actuator out and force it in or out with a screw driver where if the air locker fails, you’re sol.

 

I agree with this. I’ve been running ARB front air lockers for years and at least once a year I have to test them just to make sure they are working. Would rather have an electronic locking front with an indicator light when it’s off and on.

 

Nope. The sum of the speeds of the front wheels MUST match the sum of the speeds of the rear wheels. Each axle is tracking a path that would LIKE to have a different input speed at the pinion. This cannot happen as the tcase outputs force each axle to handle the same input speed. Therefore, the open differentials can only distribute speeds in proportion to the input speed it is required to take. Since all wheels have available traction something must give as the sum of the two wheels on an axle are forced to different total speeds than they'd ideally like to have in a turn. This becomes bind and scrub. This is also why full-time 4wd and AWD vehicles have some type of differential (open or limited slip) in the tcase.

 

So what your saying is if I lock my front and rear lockers up and drive on the pavement I won’t notice a difference between that and just having it in 4H?

And thanks for all the info. Been learning some stuff on here. I also stand corrected on the speed at which you can operate the Toyota rear locker at. I’ve never had a need to use my rear locker expect at crawl speeds so I figured they were just like the others I’ve had where they automatically turn off after hitting a certain speed.

Thanks again for the info and interested in hearing your response to the above question.