OK guys and gals, this may seem like minutia, but it is a huge problem on some of our coaches. My axles (and I think most) are retained by 8 studs with nuts and split cone wedges. Seems like a good system until you have to remove an axle. Then it can be a HUGE problem. The "standard" method is to take off all of the nuts and pound on the end of the axle with a **HUGE** sledge hammer (says that right in the manual as I recall). I have had to do this a couple of times and it takes hours if they have been on for a long time! Most recently when we had to be towed the tow truck guys spent well over an hour trying to remove them. We then installed the axles when they dropped the bus and I drove the bus about half mile to the shop. They used an electric impact and did not over tighten the nuts.
Yesterday, I went to remove the axles to repair the gaskets. They were again very hard to remove. For two of them, I had to double nut the stud and remove the stud (cone locked on the stud).
SOOOO, my question: would there be any problem with replacing the studs with bolts (being careful to make sure the bolts had good thread engagement and did not bottom out). I suspect a person would need to have a couple of guide studs to insert the axle (replaced with bolts before final installation).
Using bolts would GUARANTEE an easy removal of the cones. From an engineering standpoint, I can't see an issue if the correct length bolt was chosen. However, every truck/bus has the studs.
Thoughts?
Jim
Removed
OK, as soon as I post, I think of one possible issue. The diameter of the stud can be carefully controlled while the bolt may not have the shaft dimension controlled. That could possible affect the "locking" of the cone on the bore of the axle and the shaft of the bolt.
The stud has coarse threads in the housing and fine threads for the nuts. Obviously I will need coarse thread bolts. I will explore what the tolerances are for grade 5 and 8 bolts (as well as allen head). The split taper should accommodate some difference in diameter.
Jim
Jim, I think that the cones transfer all of the radial loads to the studs and without them the axle could shift when loads are applied. Would replacing the studs with cap head bolts do the same? Regards John L
Dallas, we were typing at the same time. My axles do not have any "jack" holes. The pounding method for my application is strictly relying on the "ringing" process to loosen the cones. With jack bolts I could see where it would help the process. For the short distance I drove, we did not worry about sealing the axles. I will get the standard gaskets and not use any type of sealant unless you think it is necessary.
John, I probably did not make myself clear. I would still use the cones with the bolts. My point with the bolts is that the extracting process (turning and moving outward, will assure that the cone will either stay on the bolt, or remain in the axle. In either case, the axle can be removed without fighting the removal of the cones.
If the bolts were the proper length, the clamping forces and shear forces should be the same (I think).
Concerning the controlled diameter of the studs, I just looked at a couple of them and the surface finish does not look like anything special.
Jim
Removed
Jim, I had 3 bad studs and replaced with grade 8 bolts course thread and they leaked , never stayed tight and the space between the 2 different type threads are larger.
I did change my cones and studs a few years back and came up with idea to drill a pull hole in the axle trust me it don't work the way Eagle axles and hubs are made LOL and Jerry Jefferson is proud of that axle.
I have 4 long studs where I made a hook and plate that goes over the studs grabs the axle you back the 4 nuts off and it pulls the axle out saw that used at Southern Oregon because David was sick of buying aluminum wheels.fwiw there is a couple on the market of different types
good luck
Clifford, I am trying to picture the puller you and SOD made. I did some searching and could not come up with anything.
I would think you would need to have the studs push on the wheel and the back of the axle. There is not much room to grab a hold on the back of the axle.
Anyone got a source for that kind of tool?
Jim
Jim my problem always is that I'm afraid to hit it hard enough for fear of smacking the studs. With the duals on it is a really awkward angle to swing a big hammer, at least for me it is. What I have found works is to have an old axle around that you can have a helper hold against the head of the stuck axle and then flail away at the exposed end of the salvage axle. Your helper is actually pretty safe too because the head of the salvage axle kind of protects him from stray whacks. Sometimes you have to really whack them hard. (the axle - not the helper)
I guess I will crack out and buy the studs, nuts, and cones.
My hope is that the studs will be long enough that I can double nut them and remove the stud if I have a problem.
Jim
Bob, I agree that trying to hit the axle is a big problem. I have gotten pretty good at it. I noticed that the guys who removed them this time hit the stud at least once.
The other issue is that my axles look like they have been through the last war. I can't believe that hitting them as much as I have has not weakened them. Might even think about carrying extras if I can find them AND afford them. They are two different lengths, so you would need to carry two.
Jim
Jim, on mine I have 3/4 of a inch between each stud on the hub to grab the axle that is where I got into trouble drilling the pull holes, for years I laid a piece of 5/8 x 2 inch plate on the studs and pulled mine with my trusty Proto puller with 1/4 inch hooks on 2 blades scratch your head you will come up with something.
If not wrong I believe OTC makes the puller for around 200 bucks.
You buy 2 axles from Jerry you would think it was 2 sacks of gold lol
good luck
Quote from: rv_safetyman on April 22, 2010, 11:14:14 AM
I have gotten pretty good at it.
I really don't want to ever get good at that job.
Quote
The other issue is that my axles look like they have been through the last war. I can't believe that hitting them as much as I have has not weakened them. Might even think about carrying extras if I can find them AND afford them. They are two different lengths, so you would need to carry two.
Each to his own but I sure wouldn't bother. I've seen a few spun axles and I can't imagine how we could ever do it in bus service.
Jim,
I just recently went through this on my 4104. I know it is probably different than your setup but I learned a couple of things.
The cones only go on four studs, not all eight, so if yours is the same that could jam four studs.
The 4104 was changed at some time after my maintenance manual was published showing the four cones, so my 4104 had no cones at all?
A too thick axle gasket could keep the "bell" reaction from working when hitting it with a hammer.
Gus, my axles have cones on all 8 studs. I think I will leave it that way since I have a lot of torque available. I had not thought about the gasket killing the "ringing" of the axle.
I looked at my studs today and I have at least two different configurations in terms of length relationships of the coarse/fire/no thread area. Some are pretty buggered up.
I am going to the truck parts place tomorrow to see what they have in the way of studs. If I am not happy with the length of the fine threads (so I can double nut/remove), I will go to my bolt supplier and see what I can find.
Jim
I'm wondering if this is another busnut duty cycle weakness?
In commercial service, the axles will be removed on some periodic maintenance cycle, that is measured in months, or at least annually.
In busnut service, they stay installed for years, or even decades.
The longer stuff stays squeezed together...?
Add in that we are less likely to re-new fasteners, and we set ourselves up for trouble the next time?
Fresh in-your-ownership fasteners, an annual tear down of the wheel-end, new gaskets and seals every time, and the trouble goes away?
happy coaching!
buswarrior
So many issues and so little time: Crap!
The cones go on all studs.
The studs have fine thread on the outside and course thread going into the wheel. If you use bolts you will have COURSE$ threads under the cone and that will aggravate the removal process.
The PROPER stud length will have a smooth, unthreaded, section in the middle that is intended as the "seating area" for the cone. IF the cone seats on threads it will gouge the threads into the cone and the axle will shift ever so slightly and that is enuf. Consider the torque on that axle in low on a hill starting out. Smooth counts. Rough bolt threads will e far worse that machine fine. The fine threads are only contacting the cone for the last couple threads. Over the years you may have had studs changed out and replaced with improper items. I have eight studs that are much to long thatks to a shop in South Dakota. The 5 bolts I got in my last visit to an extremely reputable shop and I am amazed.
Don't ever remove the nuts till you have the axle popped free. Just loosen them up a little and swing away.
This is like Goldy Locks: Too small a hammer won't work well. Too large, heavy, a hammer won't work well. It has to be the correct weight and it has to be swung like you really mean it. Size matters.
by Dallas:
I'm not saying don't replace with bolts, since I'm not an engineer, but it seems to me that the engineering has already been done, and this is the best answer possible.
You don't need to be an engineer or a D mech or have 50 years in the field. I have none of that and I have never actually read any of what I have shared. But it is true....or not. Problem is really what D shared....A freaken wheel may come off due to a deviation from standard procedure and materials.
I think even the use of the stock gasket would enter into getting the correct relationship between stud threads and cone so I would not recommend using a sealer or form a gasket in place of a proper gasket.
Be well and happy Jim, Don't forget what Clifford said, now.
John
There, now I feel better. Was it good for you? ;D
John, most of what you say makes good sense. My plan was to get bolts of a length such that the cones would seat on the un-threaded part. As I noted, I have at least two different studs. One has a very short "smooth" area.
Failure of these studs would not cause the wheel to come off. The wheel is retained on the hub and the hub is retained by the bearing set. Failure of these studs would only result in inability to transmit torque.
Buswarrior, I figured that "old age" (read fretting corrosion) was the cause of my first problem trying to get there cones out. However, these axles had been removed in the past couple of weeks. The cones were well lubed. The lube itself may contribute to the problem. A lubed wedge can really cause huge radial forces between the bolt and axle.
Hope I can get to the parts place today. Snowing here now >:( >:(.
Jim
Interesting visit at the truck parts place today. I got the gaskets, studs, cones and nuts. They did not have enough of all the parts in inventory, but ordered them for me to pick up next week.
The interesting item is the cones. The ones they sell are solid cones (not split). They said that is all they sell and that is what the axle manufacturers recommend. He said that he thought the split cones are "aftermarket".
I have mixed emotions. The cones are not snug on the stud. I suspect it will tighten a bit, but that will rely on "crushing" the cone a bit. On the positive side, I think the solid cone will release easier.
When I removed a couple of the present studs (had to remove them to get the axle out), the cone was pretty locked on the stud.
Fortunately, the new studs are a bit longer and that will let me double nut the stud to remove it, if needed.
Jim
Jim,
No, I wasn't suggesting you remove four of the cones, just telling you what my manual says. And, as I said my bus has no cones at all. There was no sign of slippage or looseness so I can only assume there was a design change after the manual was written. I also have some antique GMC heavy trucks and their manuals have the same instructions.
One thing I forgot to mention, the manual also says the cones must protrude "slightly" above the axle flange or be replaced. I can see the reason for this. However, if the cone happened to protrude a lot more than "slightly" it could be excessively crushed by the nut and make it lock up.
From my standpoint....not all that lofty a perch.....I would not use the unsplit cone. If it is solid it cannot "release" after the axle is whacked and sprung free. I think solids would be a onetime affair and possibly a real bitcX to remove. You pull the axle ever year or two so don't shoot off any toes.
The cone MUST protrude slightly or it will not squeeze the stud and prevent ALL relative movement.
The stud smooth part must be the correct length and sit slightly under the flange.
Bolts have an unthreaded area that is smaller in diameter than the threaded area. Sometimes. My U JOINTS are held on with bolts called "shoulder bolts". They have a smooth area that is the same diameter as the threaded area or possibly greater. Install them backwards and the u joint flange will twist itself and chew out the hole and destroy the flange. And this is similar in principles to the axel stud flange relationship. My point is that I don't think any bolt will fill the bill and if you are looking that hard for that bolt you might as well get the correct stud.
You are right to "correct" me. A full floating axel doesn't retain the wheel. In that case the tire wouldn't come off but if you loosened up the axle while underway you might prefer dieing in a firey crash. Figuratively. I do appreciate the thought.
John
Ahoy, Jim, All,
In my case, I loosened the nuts on the drive studs a turn or so, and 'whacked' the nuts very smartly on the side with a big hammer several times. Freed everything OK, and I was able to get each drive -- torque axle out OK.
A poor job of seating the oil seal saw me needing to remove one of them, and the method worked OK the second time.
I never did whack the axle on the end -- I'm not that good with a sledge hammer.
Sheeeesh!!! you ought to see me golf!!!!
Enjoy /s/ Bob