All-Trac Diff Lock

[AE95]

Are there special limits on when you can use the diff lock? Is there a maximum speed for it? Is it meant to be used for just short periods of time? 1988 All-Trac wagon.

[epyon22]

if your thinking of locking your diff its not good to have it locked when your turning, it will cause the inside wheel to drag and cause wear(personal experience had a lx470 with a locked diff today not good for driving)

[AE95]

i may be thinking of that. I read on this forum that the diff lock spreads the drive evenly between the front and back wheels. But i don't know if i got that right. I just wanted to know if you can use the diff lock at highway speeds, if you were on an icy road for example.

[AE95]

the other day, and it wouldn't turn off afterwards, until i put it in reverse. So i probably won't use diff lock anymore. Still wonder if its meant for use on the highway though.

[Ryland]

for my tacoma 4X2 the manual says the rear locker should only be used if youre stuck and then disengaged right away, and not to go over 5mph. practically though it seems i will use it when i feel needed, but always at low speeds. maybe someone can comment who knows about lockers. i know that some vehicles have full time lockers, so whats with that? i do know for sure that a locker is of huge value when it comes to traction.

[touringcamry]

What differential does it lock? Does it lock the center or rear differential?
Is the car full time AWD or does locking the differential engage AWD and the rest of the time the vehicle is FWD?

Locking the center differential will power the rear wheels also which spread power over the front and rear wheels which is useful for getting the vehicle moving. If it's locking them together it could be a bad thing because front and rear wheels travel different distances during a turn. It will cause slip or wear on the differential. On full time AWD cars, the center differential usually allows for some slip, ie viscous differential, because of the different distance traveled.

Locking the rear differential is useful for traction also if the differential is normally open. With an open differential, the wheel with the least traction will spin and the wheel with traction will just sit there. Lock the rear diff and it will cause both wheels to spin at the same rate so it helps you get out in some situations. Limited slip differential works in a similar fashion but it allows some slip between the two wheels.

[AE95]

I have no manual and can't find any info online, but i suspected it was meant for low speeds.

[Ukrainian102]

Yeah prolly low speeds only.

[SR5_4WD]

The defferential lock can be used at any speed. 200 if you can get it going that fast. The manual says that turning sharply induces wear on the drive components like someone already said.
To properly use it you should be going quite a slow (walking) speed when turing it on. The same goes for turning it off, except you should keep going slow until the center diff light turns off. That extra time it takes for the light to turn off is the system disengaging.
I hope this was of help, because it came out of my Toyota Owner's Manual.

[AE95]

thanks for that info. So its highway compatible afterall. Can you answer a follow up questions: is diff lock splitting the engine's power evenly between the front and rear wheels or is it making all four wheels turn in unison?

[Ukrainian102]

It's prolly center diff lock, so front and rear wheels evenly, most likely. I wouldnt really turn with it on, like SR5_4WD said.

I don't see why you'd need to use it on the highway... just putting power to two wheels is enough and more efficient.

I'd only use it if you're stuck in some mud or snow or something.

[AE95]

i'm thinking about icy highways or when theres snow for miles and miles. I imagine the diff lock gives greater traction and makes driving safer when theres ice around.

[freakinbox]

I wouldn't suggest it on the hwy. think of an offroad veichle. They use it with low speeds for greater traction in mud, dirt, rocks. but are usually unlocked for regular driving. I know hwy driving usually involves little turning but think if you ever had to avoid something, that would impare that ability

[SR5_4WD]

Originally Posted by AE95

thanks for that info. So its highway compatible afterall. Can you answer a follow up questions: is diff lock splitting the engine's power evenly between the front and rear wheels or is it making all four wheels turn in unison?

Running the power through the center diff and the driveshaft while the lock is on is moving all four wheels in unison almost 50/50. But as for when it's off, I'm not sure. I'll have to read up on it. It's OK to use it on the highway, but if it's snowing on the highway the 50/50 wont do jack shit, if you lose control, you still gonna go in the woods. I find it useful for 3 things:
1) Windy roads with snow or low traction
2) Getting up my steep driveway
3) And of course rippin some badass cyclones!