OP; You did shake the wheels at the top when it was raised and saw if they spun freely, right?

 

I haven't worked on many of the newer sealed bearing systems yet but I do know when you pull the heat shield out of an OBS the 4x4 axle does tighten up and can cause problems. Many times I will cut out the heat shield and use the center part of the shield for a spacer for the axle hub.

I was wondering about this since it was mentioned that the heat shields were removed. It may be that with the shields removed like Dave mentions the 4x4 axle is pushing out hard on the bearing pack causing the heat.

Also watching the video of the front unit bearing deal there are some washers and stuff that should be in the right spots that also may cause problems if they are in the wrong spots.

With the new bearings I would either A: get new heat shields and install them or B: make up a shim the thickness of the heat shield to put the hub/unit bearing back out in the right spot.

Also when assembling again I would look up and make super sure everything is going back together in the right spots.

 

I understand this is a wayyyy out though,

but I think that they grease in the bearings would insulate well enough against current draw and I find it hard to believe that with the weak electrical current in vehicles it would do damage to steel bearings.

now maybe If you took a spark plug wire and grounded it out on a bearing housing we might make it interesting

 

you would be surprised, like i said way out for this but a thought.
i had a camaro 15 years ago that would eat shifter cables until i repaired the body ground it only took 3 cables

 

He needs to just put those back in, they help cool everything also.

 

Yep, it's way out alright.

 

How about the backing plate for the rotor, I've seen them rust away, that is also a shim, you cant just throw them away, you need to replace it.

 

sometimes you have to think outside the box when all normal options are exhausted

 

Hot bearings on a OBS or normal axle means the axle nut is to tight. Is that possible on these unit bearings somehow? What holds the bearing together while in operation?

 

Snowseeker, you might be onto something. Back when this thread came out- https://www.ford-trucks.com/forums/7...l#post10896960 - I really tightened that bolt far. I spent a few times doing a roadside adjustment to back that bolt off after I went to far. It would heat up once I got moving for a while and the brakes would get tight (well, lock up). I wonder if it is still dragging a bit but not enough to notice. That would make sense for killing calipers and hub bearings. Maybe I should back that bolt off some more, see what happens.

 

That's gonna be a winner, I bet. Thanks again

 

Sorry, I thought it was a joke.

 

I was thinking dragging brakes was the culprit but I assumed after 8+- wheel bearings you have already checked for free wheeling while jacked up. Dragging brakes definitely would heat everything up big time and you would see it in your gas mileage. If you messed with the master cylinder I would take Snowseekers advice.

 

Backed off that bolt about a half turn. Drove the truck 40 minutes down the highway and no smoke or smell upon arrival. Drove 40 minutes home and no smoke or smell. Brake pedal goes to the floor on a cold start now... Brakes squeal now. Brake pedal gets tight after warmed up. Cross my fingers that's it

 

I was thinking about the backing plate acting as a shim but all it does is move the entire hub outward a few thousands which wouldn't affect anything and would only cause the stub axle to ride a bit deeper into the knuckle.
I too think Snowseeker was onto something and repped him already. The only thing I don't understand is if you put that many new wheel hubs in how come you never noticed any dragging wheels?