Okay ive read many posts and still don't quite understand how the 4x4 engages. Ive read this post https://blazerforum.com/m_52228/tm.htmand have got a good grasp on how it works but not everything.

My first question is why don't the shafts connected to the wheels move with the wheels (locked in)? From what i understand the shafts that go into the hubs should turn when the wheel turns.

But the post that i just linked says to tell if the t-case is ok u should put it in 4hi and try to turn the shaft by hand. But if the cars on the ground and in park and you try to turn the shaft how can it turn if its splined with the front wheel(hub).

I've only owned one other 4x4 and it was a 91 dodge power ram50 this truck had locking hubs but i don't see anything about how my blazer locks its hubs from what i understand they are always locked (spline together).

 

OK, the basics. The front axle has a disconnect in the passenger side axle tube. When disconnected, it results in a free wheeling front diff. When you engage the 4wd in the transfer case, it should lock the front driveshaft (what goes between the transfer case and the front diff housing) in, but if the front axle is not engaged (in the passenger side axle tube), when the front drive shaft spins, it will just spin the carrier and put no power to the front wheels. This is due to the open differential in the front.

So in this case, there is no locking hubs in the traditional sense, but rather, an axle disconnect in the front. If you had a locker or a posi unit in the front differential (I would not advise it with the weakness of the front aluminum diff housing), then the disconnect would be much less effective as the driver side wheel would still receive power even without the front axle being engaged (again, in the axle). The operation of the factory setup really only works properly with an open diff.

 

k this makes complete since from what i was grasping thanks for the info. But many people say to try and turn the shaft how can u do this without turning the wheel?

 

Again, as I said, if the front axle is not engaged, the front driveshaft should turn in 2HI with the NV233 transfer case. It should turn quite hard in the NV236 (auto4wd option) transfer case due to the preload on the clutch pack inside the transfer case. So with the truck off and transfer case in 2HI, that is what you should feel. When in 4wd with the truck off, you should not be able to turn the front driveshaft regardless of front axle engagement state.

 

ahh ok got it now i was mixing shafts and was thinking axle shaft and not drive and other way around feel kinda dumb but i got it now.

Thanks again for all the help.