Alright I have a 02 V6 Tracker ZR2, and I am wondering how exactly the 4wd and stock hubs work on these trucks?  I have taken a look at this article

http://www.zukiworld.com/month_030104/feature_tsb_shiftontheflyremoval.htm

And I noticed that Calmini recommends that you install manual locking hubs to use their suspension lift.  So onto the particulars of what I am wondering.

If the stock hubs don’t disengage the CV shafts when not in 4wd do they do anything?

Wouldn’t manual locking hubs disengage the CV shafts and be much easier than the article on “Shift on the fly removal�?

I really like the ease of the shift-on-the-fly, I shift it into 4wd pretty much as soon as I hit dirt so I can give the 4wd system some exercise (I don’t wheel that much, maybe 1 weekend a month).  Would it be a problem (excessive wear etc.) if I installed manual hubs and left them locked all weekend when driving both on and off-road as long as I shifted out of 4wd before hitting pavement?  Would this basically be acting the same as the stock hubs that do nothing???  This would greatly reduce the hassle of the manual locking hubs.

When I was in High School I had a Jeep and in that I had automatic locking hubs that you had to drive in reverse to unlock.  Would that do anything for the Tracker, I know my owners manual doesn’t mention anything about that.  Anyways, I think that is enough questions for now, it might be easier just to explain how the shift-on-the-fly, stock hubs and manual locking hubs would interact instead.

Thanks in advance.

What you basically have as a system is a drive flange on the end of your front axles. The axles are secured to the spindle through the splines in the flange. To release the axles for rotating when the tires do, you remove the drive flange and add the manual lockout. (I have pics in my webshots of the flange.)
To add, there should be an air pump above the front bumper, feeding air pressure to a sleeve in the differential housing. This engages the front differential.

What happens when you are in 2wd, the front tires rotate the speed of the vehicle* due to the drive flanges and the diff housing is free.. Once you pull the shifter (or push the dash button) to shift the t-case into 4wd hi, the case engages the front ds, the air pump pressurizes the sleeve (if the front tires and vehicle speed match), then you have 2 axle capability. Notice it's not exactly 4wd as the axles are open, and the tires with minimal friction, front axle and rear axle, get the torque/hp. If the front tires and vehicle speed do not match, the sleeve won't engage fully till there is. Due to tolerances, you could hear a 'pop' as it engages when there is a speed difference. This is not what you want to hear.
If you add the manual lockouts, it doesn't hurt anything if/when you leave them locked when in 2wd. Everything was designed to rotate constantly, anyways. Just note to yourself, that you can not shift on the fly when they are unlocked.

Couple good things of adding the manual lockouts: 1 - reduces the wear on the front axles, housing, etc., 2 - when you go to engage the axles to go wheeling, you get to overlook the vehicle and check other items (air pressure, tire conditions, lug nuts, lockout condition, etc).



*Notice it's not the speed of the driving tires. You can have greater tire speed than vehicle speed (spinning your tires).

Thanks Jag, very helpful info.  So the rest of the shift-on-the-fly removal article is to change the gear ratio and modify the diff so you can use a locker.

If I understand the article, its to remove the requirement of the air pump and the engagement sleeve. In doing so, you basically have a setup of a ring gear attached to a carrier. The carrier drives the axle shafts. No engagement collar required. This does several things. Provides a locker capability (if one is available for the carrier or ring/pinion combo). Removes another item which could be a potential problem. Upgrades are plentiful (if proper carrier is used).