Never had a vehicle w/locking hubs before, so have a few ?s. How does the transfer case behave with regard to the hubs? Do the hubs have to be locked to use 4WD? Does locking the hubs make the from axle work like a posi? What woud happen if only one hub was locked?

Sorry for the stupid questions, but like I said, never used manual locking hubs before and want to be smart about it before I try to use them. Any advice or explanations much appreciated!!

Now for what brought this up - funny story, this actually happened yesterday. Drove up to the house following the wife home from work just by chance. Had the dog with me in the front seat, windows down (dog likes to keep her nose in the breeze as they all do, I believe). So I keep her leash around the base of the gearshift lever in case she decides to get a little over-ambitious. Well, as soon as we pulled up beside Mom, the dumb mutt got all excited and leaped right out window in an apparent attemp to strangle herself, shifting the transfer case into neutral in the process. The wife said she looked pretty funny dangling out the window. So I yanked her back inside and got it back in gear, but in my hurry to get off the street, pulled the transfer case all the way back into 4WD. I coulda swore I heard the RF tire chirp when I let off the clutch.

How is that possible without the hubs locked?

Cheers...

 

Independant, its up to you to remember to lock or unlock them and also remember what condition they are in before you pull the t-case into gear while moving, NP205's are not sychronized like the newer t-cases.
Yes, but you can leave them unlocked and use the low range to get 2wd low.
No, its probably an open rear. It would only act like a posi if it had a posi.
On an open rear, nothing.

Couldn't even begin to guess.

 

The lockout hubs connect (or disconnect) the very ends of the axleshafts to the hub/wheel combo. Both hubs need to be locked in in order to use 4x4. Use of the hubs does not create a posi effect, it just makes the axle whole, so the power can be transmitted to the wheels---the differential still operates the same. You can shift the t-case in and out of all its ranges with the hubs un-locked...you just won't get the benefits of 4x4. The nice thing about that is, you essentially have 2wd low range with the hubs un-locked, which is real handy for manuvering heavy trailers.
Hope this helps!
Greg

 

OK great. thanks! So basically the hubs are only to engage 4WD on the front axle. Transfer case selects where the power goes and what range. Just because the 4WD light is lit up on the dash does mean it is really driving all four wheels, unless the hubs are locked. Got it...

 

The Warn hubs on my truck have a plastic strip inside the hub that acts as a support bearing when the hubs are unlocked. There is also a snap ring that does I don't know what. During cooler weather my hubs acted as if they were engaging and disengaging whenever they felt like it. It turns out that the plastic bearing strip had dislodged and jammed itself in and around the snap ring in the hub. To see if there is a dragging problem similar to this try to turn the front drive shaft by hand with the truck in 2wd and the hubs unlocked. You can observe the front axle shaft at the universal joint at the king pins. The drive shaft should turn fairly easy and both axles should move with it. If one doesn't lock the hub on the one that does move and repeat the procedure, comparing the amount of effort it takes to turn the drive shaft. If the effort is more, you may require some cleaning and greasing of your hubs. The hubs only need a light coat of grease. Too much and it will cause problems as well.
Another check would be to raise the front tire off the ground and spin it by hand. The axle should not turn unless the hub is engaged.

 

ACE,..I thing that you put it in 4 LO or 2 LO(with the hubs unlocked) witch alowed a lot more tork to the back tire's.

 

Man learn something new every day.So 4lo with hubs unlocked will be 2lo?

 

Yup! this is how you brake drivelines and axles............ or find the weak link in the rear drive train!!!if you not carfull, in a vary high traction situation

 

I've run manual hubs since 1972 when i bought my first 4wd... I was taught and also read many times in tech articles over the years, to NEVER run with only one hub locked in!!! I was also taught to NEVER run in low range "without" the hubs locked in.

In both cases there have been instances where a hub got blown doing so....

Robert

 

Can you explain this? Not sure how that would happen.

I use 4low(hubs unlocked) all of time to back trailers in or on one really nasty downhill backroad coming off the mountain where I sometimes random camp. I use 2low for extra engine braking. With the hubs unlocked there is no torque being tranfered thru them and thus no stress.

Have only one hub locked will cause the side gears in an open differential to spin like crazy untill they get hot and grenade, still no load being transfered thru the hub but lots thru the diff. Now if it had a posi or locker and it suddenly locked up while spinning I could see that blowing a hub.

 

I have used my 1978 Chevy in 4-low with the hubs un-locked many, many, many times with no issues.

It is not a good idea to travel at much over a slow walk like this, however; because, the stub axles can kinda flop around in the hubs, when not supported at their ends by the splines of the hubs being engaged.

I have had the mis-fortune to have to drive a number of vehicles with vacuum controlled front axles, and auto-locking hubs; without exception, they are all junk.

The only kind of four-wheel-drive front-axle to ever have is locking-hubs, as they are the only kind that will work dependably.

All that other junk will get you out in a mud-hole and not work.

 

have had an issue with getrag going into 5th gear in my 91.5 and NOT coming out...had to use 4wd low unlocked hubs to limp home...otherwise...have you ever tried starting from a dead stop in 5th??? vs