On my 95 F150, the book says, while rotating the hub back and forth, to tighten the adjusting nut to 50 ft. lbs., then back it off 1/4 turn. Then install the lock ring. Then tighten the lock nut to 150 ft. lbs. After that final step, I attempted to turn my wheel. I could turn it, but it took some effort. It definitely wouldn't spin by hand, just turn. I went ahead and finished the job as it was. Assuming that the bearings would "break in", and loosen up. That was 5 months and 5000 miles ago.

Now I have taken the assembly back apart to replace my front axle u-joints. When I jacked it up, the wheel was still stiff, turning by hand. And, after removing the lock and adjusting nuts, the bearing did not come out easily. It took quite a bit of effort, grabbing the hub, and pulling outward, to get the bearing to come with it.

After replacing the u-joint, I start the re-assembly process, and the bearing would not go onto the hub. I cleaned the bearing up and found black marks on the inner race, as if it may have spun on the hub. No grooves or gouges, just black markings.

I am assuming that I over-tightened the adjusting nut, but, I went by the book. So, I don't understand why it is doing this. I do recall though, that after I tightened the adjusting nut and backed it off a quarter turn, but before installing the lock nut, I did notice that the hub was turning freely. So, it seems like the adjusting nut is getting tighter as the lock nut is being torqued. But, that doesn't make sense to me since the lock ring is keyed.

Well, I guess I'm off to the parts store for another bearing cone, while I wait for a response to this thread.

 

I have found the same, that setting the preload nut extra loose is needed to compensate for the additional bearing preload that the lock nut puts into the bearings. I tighten down the preload nut a good bit while rotating the wheel to fully seat the bearing, but then I back it off until there is end-play in the bearing, install lock washer, install and crank down lock nut. If there is no end play in the bearing at this stage, I remove lock nut, remove lock washer, and loosen preload nut 1 position, then reassemble, and check for end play (with lock nut tightened down). I repeat this process until I have a minimum amount of end play. That's how my father taught me to do it, and I trust him more than a cheap service manual (Ford tech for many many years). Greased bearings and oiled bearings need different amounts of preload (greased needing less).

 

Thank you very much

 

You're welcome. I may be off a little on the greased vs oiled bearing preload requirements (I was thinking oiled pinion bearings needing notable preload vs wheel bearings needing zero preload--seems it has more to do with heat source than lubrication), but you want some end play nonetheless. This is because brake rotor heats up hub, reducing the end play in the bearing at times bc the spindle doesn't heat up like the hub. So if the wheel bearing has preload to begin with, brake heat induced expansion can lead to bearing failure.

For reference, here's a good discussion on wheel bearing preload by a bunch of machinists: bearing preload practice

 

Well, now a new bearing will not slide onto the spindle. I guess taking a file to the spindle is out of the question?

 

One thing to keep in mind, tapered roller bearings have specific procedures outlined in the manual for adjustment, and specific procedures for replacement. Make sure you're reading, and following, the right one.

That is there are important differences re-installing a used bearing, say as part of a periodic inspection and repack, versus replacing with new bearings and cones set, as an assembly. New bearings are installed with a higher initial preload. That's a one time deal only.

 

Part of my problem, is that some idiot, who owned this truck before me, took a hammer to the spindle shaft to remove the spindle. I can see the hammer marks. But, I have had these bearings off of this truck twice now. And both times, they went back on. This time, I found the bearings in the condition mentioned above, and they will not go back on. I thought the bearings were warped, but apparently not, because a new bearing does the same thing. Is it OK to file the spindle, just enough to get the bearing to go on smoothly?

 

I wouldn't worry about it. Clean it up and get going again. But I do what works, not always "by the book".

 

Emery cloth would be better than a file.

 

I remember reading those procedures and attempting as well. All I can say is that who ever wrote them I believe "assumed" the inner nut would not tighten up when torquing the locking nut to 150 lbs. Basically my opinion is that it is all hogwash. I ended up tightening the first nut kind of loose, then tightened the 2nd one while spinning either the rotor assembly or that with the tire added to a tightness that seemed reasonable basically taking out the play and a little resistance. There also needs to be a pin then inserted that will lock the 2 nuts together so that the outer nut does not loosen ...... That's my story anyways ....

 

IIRC the inner nut has a nipple on the flat of the nut. The lock ring keys into the notch on the spindle and you need to line up the nipple on the nut with a hole in the lock nut. That keeps the inner nut from turning when you tighten the outer nut.

 

Anybody got a clear pic of this locknut deal? 150 inch pounds? 150 foot pounds?

 

Lock nut with tab and holes to align w/ spindle and outer nut


Inner nut with nipple


It is 150 ft. lb. for the outer nut.

 

That's quite a lot of torque. Just curious on how that all comes together. Never seen it myself. Thanks for the pics.

The inner nut should not be moved at all after adjustment, when the locknut is torqued, or of course the preload will be buggered all to hell. Ford manual writers have to know that.

Is there something missing from the manual instructions or, it should not be necessary to deviate from them as such. See where I'm goin' with that? I like to bounce the bearing manufacturer instructions off the Ford manuals as well.

 

On my 94 the best bearing preload set up I found was to torque the first nut down until it started dragging then back it off slightly looser than I would normally prefer, after the lock ring was installed and the second nut was installed and torqued way down (didn't use a torque wrench but I'd guess 150ft/lbs) the bearing preload was pretty close to perfect every time.

Using emery cloth to clean up random hammer marks on the spindle would not concern me, If it's beyond cleaning up with emery or has been really hot I would think twice about trying to save it.

Trust me you want that outside lock nut very tight, I know from experience if it's just snug it will take out everything inside the wheel hub.... All 4x4 parts included.