94 F150 Auto locking hubs

Paul, these auto hubs have a common problem, they are all POS!! LOL Replace them auto hubs with some Warn hubs or whatever brand you like best. The auto hubs are vacuum contolled so you need to look for a vacuum leak somewhere, or the diaphrams are busted in one or both of them. So I would do like I suggested and replace the hubs with warn hubs or another brand of your choice, and make them manual locking hubs.

Ford Tech

Vacuum on a '94 F150? Don't remember that option. Just the spring-loaded POS auto-hub.

Spdloader

Vacuum hubs? What?

My bad I was thinking about the newer hub locking system. Either way, the end result is the same. Replace the hubs with new ones. Either Warn or another brand that you prefer.

Ford Tech

Mr. Ford Tech -- I tried to post this earlier and got a server error. Maybe it will go this time.

I have a 97 Mazda B4000, 5-speed, 4WD and the same thing happens to me. When I shift out of 4WD into 2WD, I often (not always) get a "Z-Z-Z-Z-Z-Z" coming from one or both front hubs. I assumed that hubs were not unlocking -- I discovered that if I stop, shift into reverse, and drive backward a few feet, the noise stops -- I guess that must unlock the hubs???

How much trouble (that is, $$$$$) is it to replace the Mazda/Ford autohubs with Warn hubs?? Are the Warn hubs autolocking??

I don't drive much in 4WD so maybe manual hubs would not be a problem.

Also -- here's another question for you.

In another thread, there was a lot of discussion about "real 4WD" and some of that discussion led me to believe that the 4WD is not REAL 4WD with all four wheels pulling.

My son had a Jeep Wrangler in which we did a lot of 4-wheeling. He did something to the rear end that allowed him to pull a knob on the dash and lock up the differential -- both wheels pulled, same speed, locked together. This was fine when driving straight ahead or making only slight deviations from straight, but, try to turn a corner and the rear end hopped like made because the inner and outer wheels were locked together.

Needless to say, he used this only for serious pulling.

When I shift my Mazda into 4WD LOW, I hear a CLUNK from the rear end as though it's shifting. Then, when I try to turn a corner -- or even make a slight turn -- in 4WD LOW -- my rear end hops just like the rear end in my son's Jeep. When I shift out of 4WD LOW I hear the same CLUNK from the rear end and I can drive normally. If I go to 4WD HIGH, there is no CLUNK and the truck takes corners the same as in 2WD, although the front end complains a bit on tight turns.

Does my Mazda have a lock-up differential in 4WD LOW???

Thanks for your time.

It is possible, but highly doubtful, unless someone owned the truck before you and set up a system so that when you engages 4L that it would lock the rearend. I have heard and seen the locking rear diffs with the pull knobs, but I havent seen anything that locks the rearend in 4L unless its and autolocker. Only way to know is to look at the rear diff and see if there are any wires or vacuum lines running to it.

Ford Tech

As for the Autolocking, the answer is NO. But Here is a page that can price out how much it should cost to replace both front hubs.

are very easy to replace. Its a matter of taking about 4-5 screws loose, greasing the new hubs, installing them, and putting screws back in. Its not all that hard to install manual hubs, but if you want autolock hubs then it will be harder to do, and cost plenty more.

Sorry forgot to answer the first question with my previous post.

Ford Tech

Thanks guys!

I guess I will replace with manual hubs. Easy job? I have done manual hubs on my F250. Is replacing the autos with manuals pretty straightforward?

Paul

Paul,

According to the WSM looks pretty much like installing the manual hubs except reverse. Looks like a couple snap rings and (possibly) a nut to remove, but follow the directions that come with the new hubs. They will tell you what to pull and what to leave.

Ford Tech

Besides the hubs, there is a kit you'll need to convert to the old style bearing pre-load nut so the manual hubs will work.

Some of the new, premium hubs include this.

Spdloader

How do you lock the hubs in 2HI if you have auto locking hubs?

If you have the variety where you have to get out of the truck and turn the hubs, you do not have auto locking hubs. If you have auto locking hubs, they only lock in 4WD, either HI or LO.

When I switch to 4WD then back to 2WD, I get the grinding you describe (so does my brother, and lots of other people), and I have to stop and go in Reverse a few feet to allow the parts to separate. It is not "proper" that one would need to drive in Reverse to separate the parts of the hub, but it seems to be more or less normal.

No, the aftermarket hubs are better BECAUSE they are not auto locking. The mode of operation with these is if you are pretty certain that you will be using 4WD, you lock the hubs manually at a location where there is relative comfort, gas station, trail head, etc. Then, as you are driving along and see the need for 4WD coming up, you simply shift the transfer case as you drive. (The rules for selecting 4LO remain unchanged.) The ONLY downside (and "downside is not the right word I am looking for) is that the front tires are driving the front drive train from the time you dial in the hubs manually until you select 4Wd with the tcase.

Your son installed a LOCKER. There are several varieties of lockers, some operate automatically (they are always engaged, and have a tendency to disengage on the street with a loud bang and a jerk to one side), and others are engaged from inside the cab using a cable (like the brakes on a bike), or by vacuum, or by electricity. If you live in the snowbelt, I advise staying away from the automatic lockers because since the tires turn at the same speed all of the time without regard to the traction under the rubber, the vehicle tends to slide easily toward the low side of the road. It is possible to manage the vehicle that has a locker (in the snow), but it is a lot of work and the risk of damage when one stops paying very close attention is great.

You describe the behavior of a locking diff, but I was not aware the Mazda had one. With locker, you can easily see that both tires on the same axle spin at the same speed. If you have one tire in the air and the other on the ground churning away trying to move you forward, and both tires are going the same speed, then you have a locker. With an open diff or a limited slip, the behaviors are different in this instance.

That would be a MANUAL locker, not an auto locker.

Toyota uses the system the OP is asking about on his Mazda. Toyota's TRD trucks have a locker that electrically powers up when 4LO is selected. Personally, my Jeep experience is that if the lockers (front and rear) are used in 4HI, the odds of actually needing 4LO all but vanish. I use 4LO mostly as a means of speed control, I can go much slower in LO, and this is beneficial to me.

The work is not difficult, EXCEPT that there is a snap ring on the inside of the current hubs that you have to remove. It is difficult to see, and you have to be able to read by braille to feel it with a tool such as a scratch awl or spring hook. Once you get the snap ring out, the rest is easy. And, the snap ring isn't hard to get, it's only difficult to see. You should know when you need to start looking for it because you will have all of the screws removed and the hub still will not come off.

My operators manual tells me to back-up for one complete tire rotation to unlock my auto-locking hubs after i'm done using 4L or 4H.

93 Bronco ( full size ) and i back up , pull forwards ,then back up again if i didn't hear the click of them un-locking the first time.

That seems to say that it is indeed "proper" that one might need to go in Reverse.

What is the actual requirement is, it is normal that one must release the stress on the front axle for the hubs ot unlock fully. I have released the stress on occasion by simply coasting while setting the 4WD back to 2WD. Often, this is all that is needed and I thought that going in Reverse was a "work around" for the times it did not unlock the front hubs by itself.

So you sound like a guy who's never read the manual AND didn't ask any of the 10 million other people who have these hubs what they do. The manual says to back up. There's a good reason for that. The manual explains what the hubs are supposed to do. They're supposed to stay locked in forever in

2HI if you don't back up.

I know you'll be tempted to reply to this, but don't. Just think about how that might be useful. I'll give you a hint - it'll be on a hard surface road where you'd need that. A person designing auto hubs to be used with a fully manual transfer case would want them to stay locked in for a reason. If Ford had made every truck with shift-on-the-fly, then the hubs wouldn't need to stay locked in.

I do not have a manual because I biught my truck on the used car market.

???

Shift on the fly happens because the hubs are locked in before the transfer case is engaged, OR because the front drive shaft is already turning at the same speed as the front tires when the hubs are locked. If the hubs are locked before hand (at the trail head or beside the road or at the gas station) then the front drive shaft will be turning at the same speed as the rear drive shaft, and the tcase can be engaged without grinding gears. If the hubs are not locked, then the front driveshaft will rely on synchronizers to enable engaging with the rear drive shaft (inside of the tcase), then as the front drive shaft subsequently starts spinning, it will match the speed of the front tires and the vacuum system (or whatever the locking mechanism is) will allow the front axles to engage (lock to) the front tires, and 4WD will be complete.

Shift on the fly and locked hubs are not related, as I just described. Manual hubs can be locked before selecting 4WD, and shift on the fly is allowed in this instance. And, the tcase can complete engaging before locking the hubs automatically, and this too allows shift on the fly. The only time when shift on the fly can not be done is when the manual front hubs are not locked before 4WD is selected with the tcase shifter(s).

Samstones right. If you engage your auto hubs by shifting to 4 Hi, and then shift to 2 Hi, your hubs are still locked untill you back up.