bad studs MC8

[rcbeam]

Found several bad studs on the drives when I got my new tires/wheels.  Ordered complete set for both sides from Luke.  Any words of wisdom or handy tips from anyway on changing them out?  Never done it before, but doesn't look to be rocket science.  About all Luke had to say was spray the brake drum screws with PB blaster or similar and let it sit overnight.

Thanks in advance,

[Bill B /bus]

Ahhh. The infamous brass screws. Yah, PB Blaster. Heat. A punch to start the screw turning. Maybe. Are you prepared to buy new bearings?  Odds are some are good but some are marginal or shot. Do you have the correct axle seal  on hand?  You may have to renew the brakes. I guess the best would be to figure on new linings, new shoes, new bearings and maybe  new drums.  That would be worst case. Any thing less would be gravy. Problem with buses is that nobody fixes anything that isn't preventing operation for money.  Then we buy them and we have to play catch up on the neglected maintenance.  The broken studs are a clue as to condition yet to be found.
You can ask Luke and others about how many parts I've bought to fix that which shouldn't have been broken.
Good luck. Let us know what you found.

Bill

[Seayfam]

My words of wisdom would be... When you are removing your axle, you need a really big hammer (sledge hammer) and don't be afraid to hit the center of your axle hard. (not with a purse) then when you get ready to remove your hub, make sure you have a transmission jack or some kind of jack to remove that heavy chunk of iron. If you don't have a new seal to put back in the hub (which I would recommend) be very carfull when pulling the hub so you don't drop the hub on the spindle and ruin the seal. Then as already mentioned, make sure all your bearings and brake components are good.

Good luck

[John316]

My brass screws were common (slotted). I couldn't get anything to get them off.

But, good news is, I finally hit the solution. I purchased a cold chisel http://www.amazon.com/Stanley-16-289-4-Inch-8-Inch-Chisel/dp/tech-data/B000NNIJBQ. However, I purchased on that would fit inside an impact rated socket. Then I put that chisel inside of the socket, and used my impact wrench to take them out. Worked very well for me.

Our axles had a place that you could pull it out with bolts. Basically there are three threaded wholes that I got bolts for. Then I cut a deep notch (with a grinder and cutting blade) through the thread on one side, that way the paint and crud that was in the whole would have somewhere to go. I would tighten it a little, then reverse directions (don't forget to back it all the way out at times to clean out your notch). That started the axles out far enough that I simply pulled them out.

FWIW, our seal between the axle and hub was made out of gasket paper. We made a new one for that seal (which is of course different then the hub seal).

Gary is spot on when he says those hubs are heavy. I can remove/move/install dully hubs myself, but they are heavy.

When you actually replace the studs, I have used a standard hydraulic press to remove/install the studs. Works well.

Now I have a question for the wise. When I removed those brass screws, I didn't replace them. My thinking was that the other hubs didn't have them and were doing fine (brass were on the front hubs). Thoughts?

God bless,

John

[gus]

My 4104 slotted drum screws came right out.

My studs were determined to remain. My hub is Al which surely tripled the effort needed. A sledge hammer did not work and I don't advise using one, there is too much risk of missing your target. I had to use heat and a 50 ton press. The heat helped, don't think they would have come out otherwise.

I used a hydraulic lift table to slide the hub onto. It is heavy, yours is surely heavier.

Be sure to replace all seals, there is too much work involved to risk using old seals.

In the future take your own torque wrench and do not let the tire jockeys tighten your wheel nuts, do it yourself.

[rcbeam]

Wow... lots to think about here.  I've read all the posts and initially had no idea what was involved.  I am still waiting for the studs to arrive from Luke and I am supposed to be on the road next Tuesday the 8th to go to Fred Hobe's.  I still work for a living so putting all of this together, I'm calling around to a few local places to see if they can do the work for me. 

As I think back on what the studs looked like, I realized that they all had threads, just that the threads on the tops were worn down some.  I figure from sliding the wheel on and off the studs over the years.  So the threads on the remaining 2/3 say of the stud was fine.  The guys at the tire shop got all of them to torque to 475-500lbs.  Looking at it this way, I actually only have one BAD stud and that was the weird one that they referred to as a 'dummy stud'.  Still not sure what a dummy stud is.

The other thing is these studs have been on here like this since probably when the p/o had the used tires put on several years ago.  Not saying they don't need to be replaced, but I wonder if some of my initial reaction to what I saw was me freakingout.  The threads on the stud were not in the same shape all around the stud, just on the top.

I'd like to stop over in Chattanooga @ the Choo-Choo and get them to replace the studs because I would trust their work.  Not sure how smart it would be to drive the 280 or so miles there like this or have the work done here by someone I don't know.

[gumpy]

Ok, some of the information in the responses is a bit over the top. Changing studs does not mean you need bearings, seals, brakes, etc. It presents you with an opportunity to inspect and correct any of this stuff, but if all you need is new studs, then just replace those.

First of all, to get the drum off, remove the 5 retaining screws. The easiest way is as follows:  Apply a generous amount of heat to the head of the screw with an acetylene torch. No need to get it cherry, but you want enough heat to penetrate down the screw. Shoot a blast of PB Blaster or WD 40 to the hot screw. Take a flat punch with a head about the same size as the screw and place the flat punch directly on the screw head and smack it a few times with a big hammer. Sometimes that all that's necessary, and a screwdriver or allen wrench (depending on the type of screw) can be used to turn the screw. If not, use a center punch or corner of small chisel along the outer edge of the screw to get it started. Then use the screwdriver to remove. Note that you should replace these screws if they are badly corroded, or you mess them up to badly getting them out. Divots from the punch or chisel don't necessarily mean the screw is ruined.

Once you get the drum off, you should be able to replace the studs on the drive axle without removing the hub. It's easier if the hub is removed, but I believe it can be done without removing them. You'll probably have to take the brakes apart and swing them out of the way so you can smack the back side of each stud to drive it out the front. Remove the backing nut, and use a 5 lb sledge to drive the stud out from behind. If it's stubborn, you can sometimes place an outer nut over the stud and torque an inner nut against the outer nut to pull the stud from the hub. You may need to apply some heat to the hub around the stud, also. Use care if you resort to a flame. Don't overdo it. You only want to expand the hub slightly.

Coat the new stud spline area with anti-seize and insert it in the hole, making sure you get the flutes on the stud to line up with those in the hole. Turn it by hand till you feel it line up. Then, use a short length of 3/4" or 1" steel pipe (whichever fits over the stud threads snugly) to fit over the stud and seat against the shoulder at the base of the thread, and using the 5 lb maul, drive the stud into the hole using short deliberate blows until you feel the stud bottom out. Do not hit the end of the stud with the hammer as this will compress the stud and expand it's diameter, and damage the threads, and your outer nuts will no longer fit. Do not pull the stud into the hole by attaching the backing nut and applying torque. This can stretch the stud and cause it to break. Seat the stud by driving it in using the piece of pipe seated up against the shoulder flange. Now attach a new washer and lock nut to the back side and torque to proper specs.

Do one at a time. Rotate the drum as you move around. Shouldn't take you more than a couple hours to replace all 10. Don't just do one or two. And replace the outer nuts while you're at it. Reinstall the brakes and drum. Coat the drum retaining screws before reinstalling. Torque the drum retaining screws in a star pattern until the drum is tight. Adjust the brakes while you have the wheels off.

Reinstall the wheels. Now you know exactly what you have on that drive axle. Repeat on the other side.

craig

[Busted Knuckle]

Craig has lined it out perfectly to do it yourself. If you still ain't comfortable doing it. I'd say take it nice and easy an stroll on down to the Choo Choo and let Joel do it.  He has the experience! I know he did 4 the tags and steers on one for me with the long studs so I could put the aluminum wheels on it. (he already had my bus there for major engine transmission leak repairs)
  BK 

[rcbeam]

Craig and BK... thx for the replies.  I certainly sounds like something I could do and sorta want to do... if it was warmer out and I was not under the wire on time.  With most things I've tackled on the bus that involve screws, I'll get all out but 1 then spend two days getting it out.  That scenario seems to be consistent. 

So I'll either have it done here or see if I can get it down to Choo-Choo.

[gus]

I agree about not replacing bearings unless they show signs of wear, overheating or scoring but I will never again remove an axle without replacing seals, auto or bus.

I've had too many old seals leak after all that work, never had a new one leak though.

[Seayfam]

I agree about not replacing bearings unless they show signs of wear, overheating or scoring but I will never again remove an axle without replacing seals, auto or bus.

I've had too many old seals leak after all that work, never had a new one leak though.

I completely agree, only $50.00 not worth the risk.

On my bus I can't just remove the drum and pull the studs. My drum is mounted to the back side of my hub. Makes for a very heavy removal with the deep drums on my bus. I bet the hub and drum on my axle weights 200lbs or more.

[rcbeam]

UPDATE.  I made some calls and took the bus to Bluegrass International Trucks in Georgtown KY.  Absolutely great group of guys.  They are an International dealership and do mostly trucks but also school buses.  They had no problem working on an old MCI.  I had them do the studs that I got from Luke, inspect the brakes, adjust slack adjusters, and check all wheel bearing and seals.  I said to let me know if they find anything wrong along the way.  They work two shifts there so they got pretty far today already.  Received the call this afternoon late for me to drive down and see what they found. 

Brakes are all ok, except the slack adjusters and s-cam assesmbly on both drives have slop in them and need replacing.
The tag axle that I felt might have bearing issues, in fact does.  When he shined his light on the oil from his finger out of it, you could see all the little metal pieces in there.
Both universals on the drive shaft are bad and they suspect the yokes our worn but can't tell for sure until they remove it.
Differential input seal and flange seal leaking... which I knew about.
The bigest issue I think was both king pins BADLY worn and tie rod ends bad.  As bad as the king pins are, no wonder she wonders a little and has so much play in the steering.  They are going to call in Axle Surgeons tomorrow to look at all of that.

He said the drive slack adjuster assemblies did not have to be done now... just wanted me to know what they found. 

I am very impressed so far with these guys.  So much better than the goof balls at S&S Truck Center I took it too last year to have the steering inspected.  They said, after I had them look at it twice, " oh the steering gear is worn out.. .everything else if fine"... which clearly is NOT the case.

So he is going to give me estimates on all the additional work tomorrow.  I was planning on heading out next Tuesday in the bus to Fred Hobe's... but now that looks to be postponed.