I've seen a few posts with 05s rear diffs going out. My question is when you select tarmac, gravel and snow, how fast are you going through to select the one you want. I was told selecting through each mode to fast isn't good while driving. When I'm driving and want to select a different mode I wait like 5 seconds between each selection and so far no problems for me.

 

I usually just set it right after I start the car.

I usually keep it in tarmac mode, but if it's wet out, or snowing, I set it before I drive off.

I'm not too intimate with the ACD and how it functions, but if it only 'changes' algorithms used to determine how the ACD operates, then on the fly mode changing at whatever speed shouldn't be a negative thing.

 

I have done alot of reading on the ACD and its still a little foggy to me, For example, what would happen if you drove around all the time with it in the snow option on dry ground? would you do some damage? I wouldn't think mitsu would do that because the average car buyer is pretty dumb, but ya never know..

 

i dont think you'll damage it. i've been doing 80mph and change settings jumping right through them to the one i want. its electronically controlled and only locks/unlocks the diff, i dont see how you can harm it by changing settings at any speed or driving in the wrong setting for the environment.

 

And I would tend to agree with that, but in the snow mode the center diff stays locked during turing for a few seconds, so on dry roads when turning what happens? While turning some wheels are spinning faster than others so where does the load go?

Just trying to learn, not trying to be argumentative...

 

Changing the setting at 80mph wouldn't be a problem, but if your pushing the button like a video game then I don't think that is good for it.
Riding around in snow mode shouldn't be a problem if it's not done all the time. All the different settings do is let the center diff slip (not let the power to the rear) and send the power to the front. Now it might cause some damage if you did this constently.

 

I have an 05 and ive switched through them pretty fast. No problems here. I would HIGHLY DOUBT that switching it fast while driving would cause dammage. Youre not activating anything mechanical, just changing the program. I would be utterly shocked if a simple, yet highly developed program such as this, didnt have safety features built in to prevent dammage. Something like this is rule number one when developing software for vehicles, especially race inspired ones.

The differential is going to lock up no matter what setting it is in, all you are changing is the duration. Theres no transfer of power from the front to rear or vise/versa.

On the other hand, I would refrain from seeing how many times you could push it in a minute while doing donuts.

My advice is change it when you think you need to, and don't give it a second thought. Nothing I have read or heard has suggested otherwise.

 

When I picked up my evo (last thursday ) My dealer told me that the differnt modes basically lock/unlock the center diff, as stated above in this post. He also told me that since it is more locked I think in gravel and snow modes, its quite bad for the center diff to drive on tarmac in those modes. It will load up the center diff, and damage it.
However I have also been told by another driver, that using gravel mode on tarmac makes the car more slidy and a lot more fun so you decide

 

i was told the same about the ACD

 

it's electrical swich, not mechanical. i wouldn't worry about choosing them on fly. i'm sure they had that on mind when they put the switch so easy to reach and change.

if it was going to damage it, mitsu would of made some sort of pre-switch for it. they usually do..

 

he acutally listens to the dealer. HAHAHHAAHAHAHA that is too funny.

 

okay when you push the button car ecu waits a 5-15 sec period to make sure your not going to punch the button again, however if you do then it will start that wait time over again. This said you can push the button as many times as you want as quick as you want, the ecu will wait untill your done and then switch to the selected option. As far as speed goes the car is smart it wont auto switch thouse over at a high rate of speed if the car deems it "a bad idea" So what this means is your ripping down the road and 100 and your hand slips and hits the button, your car will see this and wait untill you slow down or stop doing what ever it is your doing the car doesnt like.

 

omniphil wishes we could get a hold of the algorithm to really find out whats going on

On a side note... How can u verify that it is working? Last night the roads were covered with snow, we selected the snow mode and the car didnt behave any different than tarmac mode, the back end slid out easily, I'm assuming that in tarmac mode while turning in snow the front tires should spin and not the rears because the diff unlocks during cornering, and in the snow mode, it says locked for 5 or so seconds, Or at least thats what I've read on here...

Anyone else do any testing in the snow?

 

^^^ very good points

 

I change mine when stationary.