4106 Rear Hub Advice

[technomadia]

We are currently at the tire shop getting new tires/wheels put on our 4106. They discovered that one of the studs on the rear driver side was stripped, and they could not get it off.  A quick call to Clifford (thank you!!) and gave them the go ahead to grind it off.

They currently have the hub assembly on the ground while they take it to the shop to grind off (gulp). Pic just uploaded to our Facebook page at http://www.Facebook.com/technomadia

We also have placed an overnight order for a new stud & bolt from US Coach to arrive tomorrow to replace it.

If anyone has additional advice to lend, please let us know. If it is urgent (IE we need to act immediately) please call Chris at 408-667-9022

Thanks!
Cherie

[TedsBUSted]

What was the problem? Was the square head  "chewed up" on an inner nut?
If so, just for others' future reference,  a stripped "square" itself wouldn't usually be a reason to cut the stud off.
Usually there would be other options available in a tire shop, but maybe Budd experience is fading away.
I have a hunch that with his suggestion Clifford had intended for the inner nut to be cut, not the stud.

Be sure the techs grasp the hub's (unique today) lube and seal requirements.

Ted

[technomadia]

Be sure the techs grasp the hub's (unique today) lube and seal requirements.

Please urgently fill us in on what those requirements are so that I can make sure it gets done right tomorrow once the replacement stud and nut arrives from US Coach.

He said he was planning to use something called "black... <dang can't remember what he called it>" to reseal everything - he said it was commonly done.  Does this make sense to anyone?

We've got a motel for the night - w head back to the tire shop at 8AM'ish.

   - Chris

[TedsBUSted]

Of course this all has to be confirmed by the man on the ground, but originally at least, the wheel bearings were probably grease packed and the hubs sealed with an inner and outer seal.

Today, it's most common for a hub to be lubed via differential lube flow and an axle flange simply sealed with silicone. Thus, an unknowing tech could toss the outer-seal/axle-gasket to replace it with black RTV sealer, not realizing that the hub must be sealed from axle oil.

Ted

[technomadia]

Today, it's most common for a hub to be lubed via differential lube flow and an axle flange simply sealed with silicone. Thus, an unknowing tech could toss the outer-seal/axle-gasket to replace it with black RTV sealer, not realizing that the hub must be sealed from axle oil.

"Black RTV sealer" sounds like what he said he planned to use.  Is there any reason that Black RTV sealer might be useful in this job, even assuming he kept the original seals?

I am in the process of uploading and organizing photos from today here:
https://www.dropbox.com/gallery/5589663/3/Bus%20Hunt/AZ%20-%20Taxi/Yuma%20Tire%20Shop?h=c2679b

Wisdom and eyes appreciated.

   - Chris

[TedsBUSted]

Yes, a thin film of RTV would be useful at the axle flange and hub, but I'm sure the techs are well beyond needing that sort of suggestion.

However, one important point is that the old grease-packed bearing system could be unfamiliar to an otherwise  knowledgeable tech, who could then possibly assemble the bearings dry, expecting differential lube flow to wet the bearings. Of course with an outer seal installed, differential lube can't reach the bearings

Ted

[technomadia]

However, one important point is that the old grease-packed bearing system could be unfamiliar to an otherwise  knowledgeable tech, who could then possibly assemble the bearings dry, expecting differential lube flow to wet the bearings. Of course with an outer seal installed, differential lube can't reach the bearings.

I do like that the mechanic at Ed Whitehead's is open to us hanging over his shoulder, and he is enjoying working on the bus and explaining things.  He has never worked on an old bus like this before, and he is very open to suggestions and our tapping into the collective wisdom of the boards.

In addition to reassembling the hub, tomorrow he is going to show me how to change the oil.  I hope there are no surprises that come up in that undertaking...

BTW: A more organized set of photos focusing on the hub removal and the view up underneath from the rear right wheel well is now uploaded here: https://www.dropbox.com/gallery/5589663/4/Bus%20Hunt/AZ%20-%20Taxi/Yuma%20Tire%20Shop/Right%20Rear%20Hub%20Removal%20%26%20Underside%20Inspection?h=6a79fa

Thanks for chiming in!

   - Chris

[oldmansax]

Chris,

I hesitate to even reply here because I know I am paranoid & anal about how mechanical things are done. That's why I am still horsing around wheels & hubs & gears & tires & whatever at my age instead of hiring it done.      Anyway, I'll try to keep in mind you are in a difficult situation in a for hire shop & you have to be careful not to PO the mechanic.

Ted is correct about the type of hub seals. Those type of hubs used to be referred to as "dry hubs" or "dry seals" by the old timers.... although I guess that would include me, now!     As you may have noticed, there are two seals, one on the inside of the hub, & one on the outside (inner seal & outer seal). The wheel bearings are lubricated with wheel bearing grease & kept clean between these two seals. The inner seal keeps the grease in the bearing cavity and the dirt outside. The outer seal keeps the grease in the bearing cavity AND THE DIFFERENTIAL OIL FROM CONTAMINATING THE WHEEL BEARING GREASE. Both of these seals need to be in good shape. If you have the parts manual for the bus, it should show how these parts fit together and do their job. It's a bit more complicated then I want to write about here. Dry hubs need to be disassembled & checked periodically. Your manual will give you a schedule. Unless you KNOW when that was done, you should do it yourself or have someone (preferably an old timer who worked on this type of unit) do it for you. You also need to learn what needs to be done so that mechanics can't fool you.

It is easy to see if the inner seal fails because grease will show up on the back side of the tire. An outer seal failure is harder to detect because the differential oil just leaks into the bearing cavity. If there are no leaks in the differential and the oil level is low, you can be pretty sure outer seal has failed. For that reason, the differential needs to be checked to catch any seal failures before low oil costs you a differential.

Pictures make it harder to tell exactly how the repairs are being handled but it looks like your seals & bearing(s) may have been laid down on the floor of the shop instead of being kept in as sterile an environment as possible. My Dad would have beat me with a tire iron for laying a bearing down anywhere except on something clean. Any bearing left in the open like that would have been washed through three washings of gasoline (dirty, clean, & rinse) & thoroughly inspected for any sign of foreign matter before being packed with new grease ( you can't just smear grease on them & slap them in the hub) & reinstalled. You also should not handle them with your bare hands because you skin has salt residue on it & will cause microscopic cracks in the bearing face. We NEVER re-used seals if there was ANY chance of dirt having contaminated them. It's impossible to be sure you have gotten every grain of dirt out of the seal ( a grain of sand will embed itself into the seal face and surface later to scar the mating surface).

Watch how things are reassembled and ask someone who knows if it was done correctly later, after you get away from the shop. As I said, there is no use upsetting the mechanic or shop. I have had to redo things many times from shops that should have known how it was done.

Like I said, I already know I'm crazy so don't flame me for being anal about mechanical things.

Best Regards,

TOM

[longjohn]

Like Tom , I agree  after reading his post i went back and looked at the pics again and hope he wiped off the axle shaft before shoving it back in. You are in good hands here . These older "hands" will help keep you straight.   

Tom i could not help but smile at the tire iron remark.    now Pop's would have let me get it bolted all back together . then fussed the whole time till i did it right

[technomadia]

Pictures make it harder to tell exactly how the repairs are being handled but it looks like your seals & bearing(s) may have been laid down on the floor of the shop instead of being kept in as sterile an environment as possible.

Yeah, I was a little disturbed to see the bearings and axle shaft just sitting out on the shop floor. Not sterile at all.

The mechanic made it clear that he dealt with that sort of stuff all day, so I wasn't really in a position to question him much.  But I do look forward to getting tutored in the right way to do it from some of you old masters ASAP.

As long as he isn't doing anything that will cause damage in the next few hundred miles, I am hoping we are ok tomorrow...

   - Chris

[demodriver]

In that one pic is the axle splines laying on the concrete floor?

As others have said. I would cringe with the way that some of the parts are laying around.

As for the seals. I have always been told to replace the seals everytime that you pull a hub. I USUALLY AM WORKING ON DUMP TRUCKS AND ONE TON TRUCKS NOT BUS HUBS.  I am not sure how they compare.

i am surprised that they are allowing you to shadow them. Most places its a strict NO NO for liability.

best of luck, Eric

[gus]

I found two rear studs stripped on my 4104 so I went ahead and replaced all of them, it just isn't worth having to do it over again later on. If two were stripped the others were most likely over-torqued and stretched/weakened also.

It was an awful job and I really don't want to do it again.

[luvrbus]

You guys would panic if you went into a truck or heavy equipment  shop you know he is going wash the stuff and blow with air, check out the Cat dealers mobile guys rebuilding a 45,000 dollar Powershift transmission in the field I never saw one of those guys using surgical gloves on bearing or the races bet you Ted can relate to that.
You are not building computer chips or brain surgery here all this BS is going to make Chris paranoid.
Concrete floors would be better than the places I saw you dump truck drivers repair something Eric I have saw you guys with gears scattered out on news paper on the ground.
I even saw one working on a injection pump off a Cat engine on the running board he got her fixed and was up and running  LOL  

good luck

[technomadia]

i am surprised that they are allowing you to shadow them. Most places its a strict NO NO for liability.

Well, they didn't let us stay in the bus overnight in their service yard.  But at least they've let us hang out and watch the work.

  - Chris

[ArtGill]

Get an oil sample for information and to establish a base line.

Art