locking rear differential?

Ok, I'm new here, but I've had 4x4 Tacomas for several years. My most recent Taco is an 02' with the locking rear differential feature. This may be a dumb question, but why might I need rear lock differential if I have 4 wheel drive? I thought this feature was more for the pre-runners?

 

4 wheel drive is 2 wheel drive in reality.
2 wheel drive is 1 wheel drive in reality.
4 wheel drive with a locker front or rear is actually 3 wheel drive.
or locker front and rear is actually the true definaition of 4 wheel drive.

Have I confused you yet?

 

check this thread out..it will explain everything
http://www.tacomaworld.com/forum/technical-chat/9307-1-2-wheel-drive.html

 

Good morning and welcome!

You do have 4WD... and if the surface under the 4 tires was equal and all else was in perfect balance, each tire would be pulling you forward.

However, in the 'real world' where conditions are never ideal or perfect... and one of the two tires per axles can spin easier than the other, IT will get the torque and the tire on firm ground that can actually move you doesn't. This is normal 'open differentials' working so your truck can steer easily. When turning, one tire must rotate more than the other, afterall.

So, is slushy snow, mud, sand or loose rocks... you can get stuck and you will see one front and one rear tire spinning.

4WD is double the traction of 2WD because you have torque going to at least one front and one rear tire. The front has the engine over it, so that is an aid to traction as well. Still, the tire(s) that can spin the easiest gets the torque (rotation energy).

LIMITED SLIP differentials reduce the excess spinning of a loose tire so more energy can go to the traction tire. They use clutches or other mechanisms inside the differential. On '05-'08 Sport TRD Tacomas

TRACION CONTROL uses spin sensors and the brakes to slow a spinning tire down and transfer torque. On all '09+ Tacomas.

The REAR LOCKER locks together the left and right tire so the torque is equal... If one is in the air or on slushy ground, it will not rotate more than the tire on firm ground. This is a great aid to traction and ability to move you ahead. Obviously, steering is more difficult, so the locker use should be limited to getting through or up difficult places, un stuck, and turned off ASAP. On all Off Road TRD Tacomas

After market FRONT lockers are added on for real serious trail riding... all four tires rotating the same speed no matter what type of terrain is under them.

A-TRAC (Active Traction Control) is available on '09+ 4WD Off Road TRD Tacomas. It uses tire spin sensors and a hydraulic brake booster to brake a loose tire harder than the standard TRAC system and nearly match it with a traction tire to provide the traction of front and rear lockers, but without affecting steering.

Enjoy the 4WD plus Rear Locker... You will find that you can out climb and go beyond where your open rear differential 4WD could not.

 

Wow! all this info is enough to make your head spin. I'm really glad I'm not an engineer/ rocket scientist or I'd be up all night with a headache...Thanks for all of the explanations, I understand better now, and why changing my differential fluid may be a good idea!

 

That is very good explication bravo

 

Gracias!

 

This guy has forgotten more about A-trac ( & any other letter that ends in -Trac ) than I'll ever know... he knows what he's talking about...

 

Yeah DavidK is always "the man" on these issues.

 

DId i miss something how come in every thread David K is always getting bagged on .

 

ahhh ok

 

Oh hell no, David K is my AARP partner in crime !! He's done his home work, he knows his stuff pretty well. re read my quote....

 

Knowledge is king...

Way too many people who work for Toyota sales are not informed or don't do the informing on traction controls they should.

Way too many people buy a Sport or who would have bought an Off Road if they were informed correctly.

I hope to catch buyers before it is too late and they regret not getting the truck with the most traction features. Also, to help those who have the Off Road but don't realize what the traction controls do and maybe save them some money?

There is nothing wrong with the Sport if you want a sport truck. There is something wrong with salesmen who don't know their product line and mislead buyers.

When I traded my '05 for the '10, I didn't know it had A-TRAC... I had seen an early version of A-TRAC tested in Ocotillo Wells by the factory or magazine personal using an A-TRAC equipped Lexus... about 2001. They had the lexus strapped to another vehicle (there were three), and intentionally burried it in the sand.

They unhooked it from the anchor vehicle in back after it was down to the hubs in the sand at Devil's Slide. Then the Lexus (with A-TRAC activated) climbed out on its own power from being stuck. It was awesome... It took Toyota 8 more years before they put A-TRAC on the Tacoma, with Lexus, Land Cruiser, 4Runner, and FJ Cruiser getting before us.

A year ago, on my new truck's first trip to Baja, I was blown away by how much better it drove on the beach than my previous Tacomas with standard 4WD. The Trac in H4 was amazing... then I turned off the Trac and VSC in H4, and the truck got stuck (because the tires were at 32 psi).

Remembering the A-TRAC test I saw 9 years earlier, I turned on the A-TRAC and gave it some gas, the Tacoma climbed out of the stuck without my clearing away sand or deflating the tires.

It was a special moment...

From that point, I felt the need to share this 'secret' Toyota was keeping about the A-TRAC (and the TRAC in H4)... It was just too good to not talk about it!!

 

Well i wish i would have seen this post about 4 years ago or yes i would have bought the off road version. So to make up for my mistake i will have to put Arb lockers in both diffs .

 

Good idea! You will love the idea that no matter what is under your tires, all 4 will still rotate!!!

 

I've got a 2010 TacO Access Cab, V6 not SR5, no rear Diff lock.
Pre Owned, Picked it up w/ 8k mi. on it.
Got 26k now.

Wheres the best place to get a Stock Tacoma Diff lock, or should I go with something like an ARB air locker?

I've got a few friends that crawl, but they rock modded YJ, TJ's, CJ's etc. I'm just an every day driver that wants a little more out of my vehicle.

 

Air locker.

 

I have question I recently installed arb front and back. If i am on the freeway and i accidently engage the rear with my knee doing 50-60 on freeway is that a problem?

 

You would first have to turn the air compressor on to activate the ARB lockers, so most likely you would have to bump 2 switches. At least that was how my ARB system was set up in my old Jeep. This is the sequence I had to complete to activate the lockers:
1. Turn on the air compressor switch
2. Push the switch for the rear lockers
3. Once the rear lockers were engaged, I could turn on the switch for the front locker

If I just flipped the locker switch without first turning on the air compressor it would not lock anything in.

So you should be fine as long as you don't leave the compressor switch engaged.

 

If it were my truck I'd relocate that switch.