Hub Carnage

[pugslyyy]

So I decided to service my hubs, because why not? Anyway, I had noticed that my driver hub is harder to rotate than the passenger side so am expecting I may find something there.

I was figuring the passenger side would be easy - check it, maybe add a little grease, make sure the brake linings look good, etc. TBH, I'm not even sure what happened here. Any thoughts? Can I get replacement parts without buying a whole assembly?

 

[dwh]

Looks like it was only partially engaged.

Fortunately, you have a previous owner that you can use as a handy scapegoat.

 

[pugslyyy]

The issue with "locking hubs" like on the Fuso is there is no true indication of lock - it is entirely possible to have the hub in the "lock" position without it engaging.

My question is what happened to the freewheel hub centering plate (MB420185)? If something had caused it to fail, that would certainly take the gears out of center with each other and cause the wear I see on them.

Unless I am looking at it wrong, the plate failed which caused the wear on the gears and not the other way round.

 

[HazMan]

I've had that very scenario happen to me repeatedly with my front hub. Or, it's been locked and under high torque loads it "pops out" and free wheels. This happens to me on sand at low speeds.

I've checked the lock ring and springs, cleaned and regreased everything but it's still the same.

Sean

 

[pugslyyy]

Yeah I'm hoping someone can weigh in on the busted centering plate (MB420185). I get how the gears could have got buggered, just not understanding what happened with the centering plate - and I don't like not understanding why something broke!

 

[dwh]

Can you post an exploded view of that assembly? Or a link?

 

[blackduck]

View attachment hub.docx

thats the FG 07 hub
bugga'd if i know how you snapped it
all the force of a sudden engagement or disengagement would be taken by the gears

whats the state of the bearings
looks like the only thing that could deliver a good whack enough to shatter the centering plate would be sufficient play in the bearing allowing the hub to deflect putting load on the plate

 

[pugslyyy]

Can you post an exploded view of that assembly? Or a link?

Here you go. I highlighted the 3 parts that were damaged. The centering plate was pushed in (towards the truck) which was what caused it to break (I had to use a press to get it to pop out of the casing). Since everything outboard of it is actuated by springs I don't see what could have exerted enough force on it for that to happen.

 

[dwh]

Yea, like blackduck, my first instinct was a wheel bearing problem.

If I'm not mistaken (hard to tell on a phone screen) the spindle is chewed up where the outer bearing rides.

So at the moment I'm thinking we're seeing the results of a loose wheel bearing allowing a mis-alignment of the hub.

That would account for the wear on the gears, and I think heat, binding and side pressure could account for the jammed and busted centering plate. I also don't see any way for the centering plate to get hammered hard enough to jam it in place and snap it.

 

[gait]

first time out with my truck (about 6 years ago so memory faint) one hub failed to engage when I really needed it (we got stuck).

At dealer a couple of days later I was allowed into the workshop to watch. The centering plate was distorted and partly cracked (not fractured through like yours). Conclusion was the hub had been assembled incorrectly, centering plate the wrong way round, and force tightened to get it together. On assembly with new parts it took about an hour of add a part and test to achieve an operating hub. Mechanic was old school meticulouscareful. Assembly looked a bit fickle. Its been good since.

When I had to replace a king pin bearing (roadside) I had to be fairly meticulous about reassembly with springs in right sequence and parts in right orientation. I was reasonably thorough about examining parts and making sure bits slid as they should. One of those easy to get wrong but feels very different when right jobs.

I'm due to repack wheel bearings.

 

[HazMan]

Any ideas of what my hub popping out of lock is?

Worn springs behind locking ring? I'll recheck now that I can see the exploded diagram to ensure things are in the correct order.

Sean

 

[pugslyyy]

Any ideas of what my hub popping out of lock is?

Worn springs behind locking ring? I'll recheck now that I can see the exploded diagram to ensure things are in the correct order.

Sean

I would suspect the reason that it is popping out of lock is because it is not fully locking. The way the hub works, once it truly engages it isn't coming out again until you unlock the hub (or have some sort of a catastrophic failure)

 

[pugslyyy]

first time out with my truck (about 6 years ago so memory faint) one hub failed to engage when I really needed it (we got stuck).

At dealer a couple of days later I was allowed into the workshop to watch. The centering plate was distorted and partly cracked (not fractured through like yours). Conclusion was the hub had been assembled incorrectly, centering plate the wrong way round, and force tightened to get it together. On assembly with new parts it took about an hour of add a part and test to achieve an operating hub. Mechanic was old school meticulouscareful. Assembly looked a bit fickle. Its been good since.

When I had to replace a king pin bearing (roadside) I had to be fairly meticulous about reassembly with springs in right sequence and parts in right orientation. I was reasonably thorough about examining parts and making sure bits slid as they should. One of those easy to get wrong but feels very different when right jobs.

I'm due to repack wheel bearings.

Hmm, interesting that you had a problem with your centering plate as well. Can't imagine how someone could put it in backwards, though!

I'm struggling to get the driver side freewheel hub off. I've already buggered a couple of bolts.

UPDATE - Got the other freewheel hub off tonight. After a day the PB Blaster did the trick, that stuff can work miracles sometimes. From first inspection that side looks fine. Was it normal for the hubs to be factory packed with blue (marine) grease?

 

[gait]

thought I had some old photos, but not to be. I didn't have the other damage on the shaft shown in your photos. My recollection is of replacing ....657 and ....658 but it was a long time ago .... Mechanic did mention a large amount of force had been used to assemble the hub and it didn't come apart easily.

 

[pugslyyy]

I got the other hub completely off today, after calling timeout to go and make a proper hub nut removal tool. It was torqued way over the specified 18 ft-lbs

Interestingly, it looks like both lock nuts had been manipulated with a punch and hammer in the past.