My Auto (vacuum lock) Hubs do not work... I'll troubleshoot that when weather improves.

4wd with hubs manually locked works but I hear an awful noise and I'm afraid I'm going to tear something up if I keep using 4wd.

Pulled the front end into my garage (whole truck won't fit) and checked u-joints, their tight.

Jacked up driver side and checked ball joints, their tight.

When spinning the wheels back & forth I could hear some clunking on the passenger side.

Jacked up the passenger side and the ball joints are tight but when spinning the wheels back and forth I noticed the wheel moves first then the shaft so when going back and forth there is some slop... maybe a spline issue?

Jacked the drivers side up again and when spinning the wheels back and forth the wheel and shaft move together, no slop.

I am by myself for troubleshooting and was wondering what else I can do to isolate the problem so I can get the right parts before I start tearing it apart.

 

Sounds like you have a bad hub probably the pass side , On mine I took off the junk factory hubs and put on warn manual hubs you will lose the auto lock feature but most of the time that doesnt work anyway...

 

Took both of the stock auto/lock hubs off to inspect and it appears to the untrained eye that everything is fine; no obvious spline wear, no metal filings etc.

I decided to order WARN Premium Hubs... had them on other trucks and they haven't failed me.

Is there anything else that might cause the wheel / axle lag I described?

 

The only thing that connects the wheel and the axle shaft is the hubs and my guess is if there is a lag from when you spin the wheel and when the axle shaft spins that it would have to be the hub.

 

Good to know, thank you.

 

X2 on the hub

 

Installed New Warn Premium Hubs and it didn't make any difference; could have saved a couple hundred bucks for other parts but they sure are fancy looking!

What would happen if I just locked one side drove a little to check noises and then the other side. Will that hurt anything?

If I hear the noise with one side locked but not the other what would that indicate?

If I hear the noise regardless of which side is locked in would that indicate the problem is in the differential or transfer case.

 

Double check your U-joint behind the wheel. Mine seemed tight also, but the needles were completely destroyed. If you still have that much slop before the axle starts moving the only thing left is the universal joint.

 

Even if they feel tight, crud may have gotten in there and froze up the needle bearings. Short of removing everything and then disassembling the shafts how could you tell the joints were bad?

I have lots of time but not lots of money so I don't want to replace perfectly good parts, as I may have done with my locking hubs.

 

If they are bad enough to be making noise, it should be easy to tell. Mine were grinding pretty loud. I had to look close, but I could see the one cap was dry of grease, the seal was shot, and rust was falling out of where the needles are supposed to be.

 

That's why I would take it apart by pulling out the unit bearing and the axle shaft. It's probably the only sure way to tell if the u-joint is bad or not. Replacement U-joint is not that expensive.

 

Maybe a broken shaft?? and binding with other half when turning to give the impression that its ok?? Kinda stumped too
But like others have said ..take it apart before you buy anything to see exactly what it is.

 

I tore everything down and found that there was no thrust washer (thick one) on the drivers side and the stub race surface that the hub assembly spindle bearing rides on was marred and the spindle bearing movement was considerably rougher than the passenger side.

I'm replacing all the seals on both shafts and the stub, spindle bearing and u-joint on the driver side. Probably should replace the passenger side u-joint while I'm in there but everything on the passenger side looks newer, maybe replaced by the PO.

I noticed the passenger side metal dust shield that is next to the knuckle seal is missing and I destroyed the drivers side when trying to remove it from the old shaft. How important is it to replace these?

 

They are all important, there are no unnecessary seals in there

 

I noticed the passenger side metal dust shield that is next to the knuckle seal is missing and I destroyed the drivers side when trying to remove it from the old shaft. How important is it to replace these?

IMO - not very, on those seals. If you do a lot of mud-bogging, then yes. There are MANY Fords out there with dust seals dangling off the shaft. This dust seal keeps dirt out of the axle tube, where it can migrate up to the real oil seal, which is located closer to the diff.