It will trash the transfer case. In AWD models it spins 100% of the time. There is no unlocking and locking the vehicle into 4wd. With 4wd, you can put it into hi or low gear in 4wd. Trust us on this. I mean you could put them on, but you will be buying a new transmission and transfer case a short while later.
Sent from my SM-N900V using proboards
locking hubsThe Montero Sport from '97-'05 came with two transfer cases. AWD/4WD and 4WD/2WD.
AWD t-case modes -
AWD
4WD High
4WD Lo
4WD/2WD t-case modes -
2WD
4WD High
4WD Lo
All Mitsu Sport t-cases are locking transfer cases BUT ONLY in 4WD (either High or Lo). They work just like locking differentials. When the transfer case is in 4WD, the front and rear output shafts are mechanically locked together. Both turn at the exact same speed all the time.
In AWD the power it transmitted to the front and rear output shafts though a 'center differential' (in this case, a viscous coupling). This setup works the same as a rear (open or LS) differential. The input and output shafts on the t-case are not mechanically locked together allowing the front and rear to work somewhat independently of each other.
Under normal operation, the front and rear wheels travel a different distance - its NEVER 100% exactly the same. There are several reasons such as different tire diameter (because of wear) or slippage. On an axle the differential equalizes this effect. In an AWD transfer case its the center differential that equalizes differences between the front and rear axles.
In an open or limited slip differential in an axle, if traction is lost on one wheel most or all of the power is directed to the tire that is slipping. i.e. If a tire hits a patch of ice, it slips and the opposing tire stops turning until the slipping tire gains traction.
In a Sport AWD transfer case, the behavior is more like that of a limited slip differential. Because the front and rear are not mechanically tied together as in the 4WD setup, most of the power from the transmission goes into the t-case and is directed towards the end that is 'slipping'.
The problem here is that with a viscous coupling center differential, this slipping creates an ENORMOUS amount of heat in the t-case and heat is the primary enemy of this type of center differential.
So, there are two reasons why you CAN NOT EVER run locking hubs in the unlocked position in all wheel drive.
#1 As BD pointed out, you would quickly fry (literally) your transfer case. I'm guessing it wouldn't take 10-15 miles.
#2 Driving would be a little problematic since most of the power would be going to the disconnected front end. Might make getting out of the driveway a bit difficult.
That is precisely what putting the transfer case into whatever range does. Shifting into 4WD 'locks' the t-case in 4WD. In reverse, shifting into AWD 'locks' the t-case into all wheel drive. There is no provision for the transfer case to 'automatically' switch between AWD, 4WD or 2WD.
That said, yes, it is possible to put an AWD t-case in 4WD and then use manual locking hubs to lock/unlock the front wheels - BUT ONLY IN 4WD!
So, on the street ...
What it WILL do, however, is if you wheel your AWD Sport, while in 4WD it will allow you to disconnect one or both front wheels from the drive train. This is a negligible benefit unless you also have a locking front differential. (Turning tight corners in a front locked Sport with IFS can be extremely challenging - the solution is to unlock one hub while leaving the differentials locked.) If you managed to blow a CV as I did 14 miles in on a trail and you need 4LO gearing to get back out, you can pull the blown CV shaft, plug the diff hole up with rags, disconnect the other side locking hub, and still have 4LO gearing but with only the rear axle driving the vehicle - effectively ending up with 2LO.
AGAIN, if you forget or someone else forgets - dealership, shop, your wife ... - and puts it in AWD with the front hubs unlocked, that'll be the end of your transfer case. Or if its in AWD and your kids decide it'd be fun to play with one of your hubs while your Sport is parked in the driveway ....
Also, keep in mind that manual hubs don't always lock or unlock when they're supposed to and sometimes they'll unlock or lock on their own.
I would not do this to my '03 AWD
FOR ANY REASON and I strongly recommend against installing manual locking hubs on ANY AWD vehicle. Putting manual locking hubs on an AWD is a ginormous repair bill waiting to happen.
Edward