I got a 2003 blazer that had a bad input shaft seal and trans oil ruined pretty much all vacuum related actuators vacuum lines any way i put a seal in the transfer case a new vacuum switch replaced all the hoses and when it came to the 4x4 actuator it was trashed and torn up but ran low on cash so i just blocked the vacuum hose running to the actuator till i can afford a new one and i dont drive it my gf. does but when i drove it the other day it almost felt like it was in 4 wheel drive or at least the drivers front feels like its engaged is that possable or any input on this would be appreciated im gonna tackle it this week end little info in manual about it thank you

 

Deleted because of brain fart

 

If just the front axle is engaging, you'll never really notice it unless something is REALLY messed up in your front diff like bearings or the ring and pinion gears themselves... Maybe a little hit on MPG like mentioned, but hardly noticeable. Under normal driving conditions, while driving you're still spinning the front CV shafts and differential internals, even the front driveshaft spins while driving in 2wd, but that's just because of internal friction in the differential that's unavoidable unless you have manual locking hubs at the wheels, something I wish GM would have offered as an option personally... There's still a differential set of gearing in the front just like there is in the rear, so from left to right, the wheels are completely independent of each other (aside from the gearing connection in the differential which supplies torque to either side when in 4wd), so turning will not make a difference.

What causes the binding is when the transfer case IS locked into 4wd AND the front diff is engaged; both engaged will create the bind, if just one or the other is there will be no bind. There is no differential action between the front and rear outputs of the transfercase. When you make a turn, the front travels further in a larger loop than the rear. THAT is what causes the binding when in 4wd.

The only time turning is going to cause binding if the transfercase is not engaged is if you have a full time locked differential gearing in the front or rear diff assembly, something that NO Blazer or S10 ever came with (there's the G80 mechanical locker option for the rear that engages when wheel slip is present, but until it engages, the rear is still an open diff). Just like when 4x4 is engaged, even if you're in 2wd and either diff is locked, you'll get binding which will result in wheel chatter or hopping, because the outside wheel is traveling further and faster than the inside wheel in a turn, and because the differential is locked the gearing doesn't allow different speeds between the wheels.

The Oldsmobile Bravada operates like a Blazer with full time Auto 4x4. The front diff assembly has NO disconnect. There is no vacuum actuator with a cable going down to the front diff, no vacuum switch on the transfercase, there is just a solid tube and solid shaft on the passenger side of the front carrier. The 4wd (or basically AWD) just kicks in when the rear wheel speed sensors detect slipping, then the transfercase gauges and applies power to the front diff, just like Auto 4x4 in a Blazer or S10. Because of the lack of components and therefore reduced failure points, the Bravada half shaft is a common swap for a 4x4 S10 or Blazer; I've got one in the garage to put on my 04, just haven't gotten around to it because I haven't had any issues with my 4x4 as of yet :P

OP, if you don't have the front diff vacuum actuator hooked up, the only way the front diff is going to be engaged is if you pull the cable that's on that actuator and tied it off; that would engage the front diff. But even then, you wouldn't really notice it like I mentioned before, unless there's something seriously wrong with your front diff, OR your transfercase is engaged in 4wd.

Put the truck on pavement (in a clear parking lot) and try to make a slow circle either left or right. You should be able to idle the truck in a circle without issues. If the truck is in 4wd there's binding, you will have to actually give it some gas to power through the binding, that's when the tire chattering/barking/hopping will start and you'll know for a fact that it's stuck in 4wd for some reason.

 

Makes perfect sense. Got rid of my comments above so not to confuse anyone who sees this in the future.