I've been reading through my Ford book I got with my 1984 F250 SC. It says that unless I have lockers in the lock position in the front, I shouldn't engage 4x4. It also states that it shouldn't be engaged going more than 40 mph. I know that to engage low one needs to be stopped, but why is it that 4h requires the hubs to be locked and speed to be low. Is that something to do with gearing rations?

 

The lockin of the hubs actually links the wheels to the axle sort of speak. Your front wheels are almost free spinnin on the hubs till you lock the hubs. But I could just be speekin out my a$$ here.

 

Interesting, I just never knew because I know in other trucks they just hit the 4x4 either while in motion or before they go and its np. I guess they probably have some time of inner/posi locker on front and rear for this purpose.

 

You mean the automatic hubs? They work the same for the most part just its electrically locked into place instead of a manual turnlock. Im goin off of the pre-97 automatic hubs of coarse.

 

As was stated, the front wheels spin freely until the hubs are locked in place. Our trucks
have manual-locking hubs whereas this is done for you by electric motors in modern
vehicles.

Moving the lever into 4wd merely engages the front driveshaft at the transfer case (which
then sends power to the front axle, the wheels get power if the hubs are locked into place).

 

The main thing you don't want to do, is pull the lever back from 2wd to 4H while moving and the front hubs unlocked. With the front hubs unlocked, your front driveshaft and all the moving parts up front are not moving. Trying to engage into 4wd while this stuff is not moving(but the truck is moving) will give you lots of bad noises in the transfer case.

If your hubs are locked in, even if you are in 2wd, the front driveshaft and all the front end parts are moving because the front tires are turning them through the hubs. So engaging into 4h will not be a problem while moving, since the front end parts are already turning.

The fancy pushbutton 4wd systems can get away with engaging the 4wd while moving, and the auto hubs unlocked, because they have special transfer cases with electric clutches inside. When you push the button, the 4wd computer engages the clutch inside, which brings the frontend pieces up to speed first before it then tells the electric shift motor to shift to 4wd.

 

Thanks a bunch I appreciate it! What would you reccomend for speed to engage the tc? Say I have the hubs locked and am doing 40 or so do I just let off the gas a tad and shift the tc then I can drive it in 4x4?

 

Usually what happens is you already have it in 4wd, getting out of a field or a snowy driveway, and up a side road or something. Once you get out on the main road, you can just push the lever up into 2wd. If you start getting into some bad stuff again, you can slow down and pull it back into 4wd. There is really no reason to be doing 55mph down a dry road and suddenly decide to pull it into 4wd.

Once thing I do recommend is if you are on a main road that is dry and in good shape, and need to make a sharp turn onto a side road or driveway where you need 4wd, it's best to get turned first on the dry road before engaging 4wd. Sometimes you can't, and then you will know what I am talking about. When it's in 4wd and you make a sharp turn on dry pavement, the truck will jump and buck, and you can break something if you are not careful.

 

These trucks came with two types of Hub systems.

Standard hubs, which you have to turn manually from Free to Lock, and back.

Automatic Hubs: Which are nothing like the electrical automatic hubs you are used to.

Proceedure with Automatic Locking Hubs of this vintage.

FOUR WHEEL DRIVE: The Vehicle must be stopped when you first shift into 4x4. Place the transmission in neutral and the transfere case shifter in the 4H or 4L position. The Hubs will automatically lock when the vehicle is driven forward. The transfere case may then be shifted between 2H and 4H with the vehicle moving as long as the automatic hubs remain engaged. The automatic hubs will remain engaged untill disengaged by the proceedure below.

TWO WHEEL DRIVE: Place the transfere case in 2h position. To disengage the automatic locking hubs, shift the transmission to move the vehicle in the opposite direction (forward or reverse) of the previous movement, and drive a minimum of ten feet (three meters). Always disengage the automatic hub locks before driving on dry, hard surface roads.


Limited Slip or (positrac GM term) is an option on both the front or rear axles. Most with limited slip were ordered for the rear axle only, and was an option on two wheel drive only models, but some 4x4s have it for both front and back.

 

I like the limited slip. The automatic, hubs are something that I wondered about. I remember seeing my uncle having to do that procedure in his Chevy but my other uncle in his Dodge didn't have to. I'd rather have manual hubs then the auto ones with the huge process.

 

I had never heard of "automatic" hubs in this year range before, how does one determine
which variant he has? I'd guess if you have the ***** on the hubs then they're manual,
eh? Do these "automatic" things also have manual override *****?

Looking at the instructions for activating the "automatic" hubs, I can see why they never
took off in the marketplace....

 

Aftermarket installation more than likely. I know my uncles Chevrolet has them. He used to tell my aunt every time how to use the 4x4 and she would get so mad but I see why he did.

 

in high school i had a buddy with a ranger with auto hubs. it couldn't have been newer than an 88 and he had auto locking hubs. it was kinda dumb. we'd have to stop the truck, he'd press a button to engage the 4x4, move forward and that was it. we just assumed it was engaged. to dissengage it, he had to stop, press the 4x4 button, and then reverse like 15 feet or so. and again, we just assumed it was disengaged. personally i love having manual hubs as i know it's either in or out. although i do get nervous everytime i come to my truck after i was parked in a lot that some dip-poop might have engaged the hubs.

 

Why not just check it before you roll? Its what I do well not for that reason presently, but my check will include that.

 

i guess cause i simply shouldn't have to. do you do a walk around your truck everytime you get in it when it wasn't parked on home turf and look for evidence of schenanigans?