I test drove a 2002 F250 4x4 SRW V10 3.73 with LS today and either the 4x4 doesn't work or it is way too smooth.

Is the 4x4 **** switch on-the-fly or is this only-in-neutral? I would hope that it is on-the-fly.

If it is on-the-fly. Below what speed does 4x4 Hi actually engage? While going about 10 miles - I turn the **** - the 4x4 indicator light comes on solid. However it refuse to get into 4x4. On ashpalt in a tight turn. I was unable to get the vehicle to gitter. The axle felt totally open.

As for 4x4 Lo. Is that also on-the-fly too? Most vehicle I think it is only-in-neutral.

Next the salesperson take it for a spin. He put the vehicle in neutral. Switch to 4x4 Hi. The same. Still smooth to me. Salesperson say he felt some gitter. Yeal rite! Next he put the vehicle in neutral. Switch to 4x4 Lo. Finally the vehicle did get some gitter.

In my past experience. Tight turns on asphalt. 4x4 Hi will cause some gitter and 4x4 Lo will cause some serious gitter - almost undriveable. Please reafffirm this.

Does your 4x4 act like this too? or different?

 

hubs? The one I am getting has had manual hubs put on it, so they had to be locked in. Yes 4 low, you need to be in neutral with foot on brake, to go low. You should be able to tell it in 4 high, especially around parking lot slow. I can feel the front feels grabbin.

anyone else?

 

If you are on pavement, the 4x4 high should definitely kick back on you. It's not that smooth. So something is wrong, and it's almost always the auto hubs.

So, test drive it again, but manually lock the hubs. The hubs on these trucks have AUTO and LOCK positions. Just turn them both to LOCK and try it again. Look at the hubs carefully though, because the label tells you the direction to turn it, not the current position. I find it confusing so I've marked them with an A and an L in the actual position to save my fragile mind.

Here is how I test to see if 4x4 is locked up. Find a safe area with a curb, the normal curb of 8" high or so. Lock into 4x4 and then drive STRAIGHT up against the curb with the front tires. I like a straight in angle. Just nudge up against the curb and stop. Then give her some throttle. If you are in 4x2, you'll spin the rear tires. If you are in 4x4 you will climb right over that curb like it isn't even there. This is a particularly fun test when you don't yet own the truck. But I've done it with my own and never hurt anything.

But heck, we already know it's the hubs.

Bill

 

Bill, i did not know about the hubs. I just assumed because i saw that they could ce turned they were manual, well that and the fact that the vaccum line is not connected. I bet i just bought a truck with junk hubs, thats my luck.

 

Yep on asphalt in a tight turn. 4x4 Hi does not kick back.

Below is a photo of how the gear switch looks like.

I am not sure how to "manually" lock the hubs or auto the hubs. Please explain further.

BTW. What exactly are hubs? Sorry for my lack of techniciality.

 

It is in the center of the wheel. When you are looking at the wheel (tire), right in the middle there should be a **** that you can turn... Hope this helps...

 

What year truck?

I think the Superduty came with either 1) standard 4x4 floor shifter with manual locking hubs, or 2) ESOF Electronic Shift On the Fly with a dash mounted selector switch and automatic front hubs.

But, the front hubs are known to be trouble prone and are often swapped out for Warn or Milemarker manual hubs, because they are stronger and trouble free. Except you got to get out of the truck to engage them. So if your new truck is a few years old, you might consider the manual hubs an advantage rather than a shortcoming. On the other hand, if the truck is '05 or newer, you need the original hubs because I don't think aftermarket is available yet.

On the other hand, if you have a floor shifter, then you had manual hubs from the factory.

Bill

 

Ok - now I know what/where the hubs are.

Can someone explain what exactly happens to the hub in AUTO mode and LOCK mode.

Thanks.

 

They look like this:


Turn the **** to AUTO and the hubs are free-wheeling, IE, your front wheels can spin independently of the drive system. Also in AUTO, if you put the truck in 4 wheel drive (high or low range) the hub locks into solid engagement with the drive system, thereby giving you front wheel drive. Turn the **** to LOCK and the hubs are engaged with the drive axle whether the truck is in 4 wheel drive or not, although you won't actually be driving the front axle unless you engage 4x4 on the dash.

Sounds like you need to spend an evening with your owners manual. No offense, but that is pretty basic stuff and covered in depth in the manual.

Bill

 

Let me rephrase. What situation would you use AUTO mode and what situation would you use LOCK mode?

And when you do put the vehicle into 4x4. How do the hubs know when to lock if it is in AUTO mode. It is there a sensor in the hub?

Thanks you for your patiences.

 

"lock" overrides the auto function. Auto relies on the vacuum system operating properly.


if its in Auto and you you flip the switch to 4wd it should work, but if you have a vac problem, you're still in 2wd

if its in Lock, and you flip the switch, you'll get 4wd regardless of the vac sys.

mine were all F'ed up on my 02, So i rolled the whole winter in "lock"

 

Thanks for the thorough explanation. Looks like a pretty nice setup.

AUTO MODE is pretty impressive as long as it works properly. This free the front axle from rotational mass while in 2WD.