I was able to use a lift yesterday and install some new shocks on my Blazer. While I was under there I checked out some other things and topped off fluids in the T-case and rear differential. Anyway, I grabbed the drive shafts to check for play and check out the u-joints. I noticed that the front DS was acting like it was engaged. I know that on a 92 S10 I had the front DS would not spin unless it was in 4wd. My truck was not in 4wd at the time and my 4wd seems to work flawlessly as well. I didn't know if something was different with the Autotrac NP236 case that kept the front DS engaged at all times. If not what could be wrong? Thanks for the help.

 

The clutch pack in the NV236 transfer case is preloaded which will cause some drag on the front shaft even in 2HI. It is not fully locked up.

 

So I shouldn't be able to turn it at all by hand correct? Thank you.

 

I just fixed my 4x4 today and when I was loosening the bolts on my front shaft it did move freely with some pressure. It shouldn't spin really easily but if you grabbed it with two hands and twisted it it should move with some drag like swartlkk said

 

Hmmm...well mine wasn't moving at all. When I would try to rotate the front DS the rear DS would move a little as well. Sound like something could be wrong?

 

Maybe your 4x4 isn't disengaging ? If you can have someone look under the truck while you drive slowly and see if the front shaft is moving in 2 hi. But please don't run them over, I'd feel bad

 

The front shaft will always spin in an NV236 transfer case. If there isn't a good bit of resistance (turning it by hand should be a real chore, not easy), then the clutch pack could be damaged and/or shimmed improperly resulting in a lack of preload.

 

Alright sounds good. Thanks for the information!

 

this may help, i removed the front drivshaft U-strap bolts, and did not have to hold the drive shaft at all, then had to insert a large screw driver in the yoke to apply enough torque to get to the other U-strap bolts.
I know there is a preload in the NV236 transfer case, i just find it a little
much to be that tight...hope it helps