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I was Harbor Frieght and they had a set of 6 ton jack stands which made me think If I had four of them could I keep the weight of the coach off the suspension system. So what is the weight of the chassis on a 1992 40'XL real wood cabinets and standard options?
GregM
Greg our 40XL weighed in at 42000. That was full of fuel and water.
Greg, if you have steel salvage yard close you can get some pretty cheap stands there. I have taken
some 3 ½ x 1/4 inch pipe and cut to length to stand the bus on when in the barn. If you need the
lengths, let me know. I raise mine up above ride height, so I can crawl under it easy.
Greg,
Fast Roger and I have an alternative to Dale's excelent method. We got some air over hydraulic jacks from Harbor Freight
http://www.harborfreight.com/cpi/cta...emnumber=95553
and when the jack is under the body support points, and the center screw extended they almost touch the support point. Now you can let the air out of the system and the bus will be supported like Dale's is, or you can air up the jack and literally raise the wheels from the ground and never get under it while it is being raised. Once the jack is extended you can put blocks under the wheels, or do what you need to do. The jacks are not stands so it is best to never work under the bus with the jacks extended, but they do provide some additional advantages over stands only, and at the price they are a good investment.
When I work under the bus I just use them with the jack fully down and the screw extended so they are functioning like stands.
Those 6 ton harbor freight jack stands, if you read the box carefully, can hold 6 tons for the pair, or 3 tons each. That is 6000 pounds each.
So divide 42,000 pounds by 6000 pounds and you would need 7 of them.
Now, how to space them out so they hold the weight evenly with 7.....
Peter, we all know that your the engineer....can't you just tell us? :)
Right on Jon- One or two came from Harbor Freight and I did buy some of mine from Northern. They sent an email coupon once up on a time and I took advantage of the sale prices. So add Northern to the list. try them you'll love em :cool:
Joe my rig is around the same weight, what I was wondering was what the weight of the coach that is being held up by the airbags.
Jon I have one of those jack looks like I need to go back and buy another one.
Thanks Peter I was wondering about that.
Dale How big a pad do you have on the bottom of your stands.
Greg
I believe 10 ton jacks should be the minimum to use because of weight unbalance as you lift. Also, I beieve hydraulic jacks should not be used for permanant or even temp support without a stationary block . I watched as a mechanic went under my coach with only the air bags llifted, he felt at ease doing this but I would not.
Greg, I don't have any pads on the bottom or the top, just the pipe. I'm sitting on a concrete floor. I use the air bags to jack up the bus and then set the four pipes in place and thats it.
Gary, you would be amazed at how many folks will go under a bus that has been raised on its air bags. When I am under mine IN THE PIT I still put the jacks (jack down, adjusting screw fully extended) under the support point. At least that way I have a total mechanical support that cannot possibly have a hydraulic failure.
When I work on the suspension, or any part of the air system, I have two jacks under the support point, as we did when Roger and I changed air bags on our buses.
I have had my bus raised up by the Detroit/Allison dealer and like Prevost they used the four floor lifts that go under the tires with a pair of forks. Unlike Prevost the forks under the drive axle went under a single tire instead of the pair of tires. I would be scared to death that the tire would blow and the sudden shift would bring the whole thing down but they were totally unconcerned. The only thing I did although it probably didn't make a bit of difference was to dump the air from the air bags so the drive axle air bags were not totally collapsed with full air pressure like the tires were.
Okay Dale, how long are the pipes? :confused:
My back two pipe stands are 14 inches and the front two are 12 inches long
I used 3 and 1/2 inch dia. and 1/4 inch wall thickness.
Dale,
Where exactly would you place the 4 tubes? I hope you don't mind, but I'm borrowing your signature style. I like the info you put in yours, and am trying it out.
Ray
If there is enough interest, and we can get a set of dimensions that would be universal I can see if the factory can produce them and ship them here for pick up at the Sevierville rally.
Once I have the quantity and size info I'll get prices. They will be made of 4 X 4 X 3/16 thick steel, and I would add a larger base plate to distribut the load with gussets to the corners to add stability.
A set could have one height for the fronts and another for the rears, unless we can come up with an adjustable screw substantial enough for the weight.
Can we have an expression of interest?
Supports.....
ps..you can put the front ones behind the tires, there is a mud flap to to hinder placement, but not bad. You can weld a two foot handle to the pipe, so you don't have to reach under so far.
Jon,
I would be interested in a set, however I'm not sure I'm gonna be able to make Seiverville, but maybe we could have a separate shipment for the west coast rally?
I am planning on Pahrump but these will not be lightweights. Let's get the total count on sets of stands and see if it is possible to carry the ones for the west coast.
Dale, you have better photo skills than I do and I would suggest you take series of photos and add an article to the POG site.
The placement is shown in the Prevost owner's manual, but a picture is infinitely more valuable.
The key to placement of supports is to be under a vertical member of the axle subframes. Supporting the coach under any other point can be very dangerous. Also, if the axles with the emergency brakes are to be off the ground the bus has nothing to stop it from rolling, so it is important to either be completely level on the floor or to chock the front axle.
Dale, Are your supports tall enough for you to get under the coach on a creeper with a greasegun?
One of those bone creepers would work, I think. I don't use a creeper. I try to keep my floor clean and wear a lightweight coverall that I keep in one of the bays.
I want to echo what Dale said and add a little for those who are contemplating doing some work under their coach.
Until we moved to TN, for 10 years I did all my coach repairs and maintenance on a barn floor. By raising the coach on the air bags and blocking it with hardwood, I did everything from oil changes and grease jobs to air bag replacement.
I would lay on a creeper at the front bumper and scoot into the area between the front wheels where I could sit up and get access to whatever I needed.
Ditto with the rear, and once I was in the area between the rear wheels I could also do whatever I needed. The areas between wheels are fairly open so it is possible to change brake chambers, suspension valves, air bags, service the air dryer, replace hoses, lube the grease fittings, etc.
I have the hydraulic jacks which work very well, but I also built some ramps that I like to use when working under the bus (that I no longer have) for extended periods of time.
I am now trying to decide if I want to install a pit in the slab I am preparing to pour in the next couple weeks. Not sure if I willl use the pit enough to justify the extra work and expense to build it, especially now that I have the ramps.
I think one would have a great sense of security working under a bus supported like that.
They look a little heavy but I suppose the correct storage spot in the garage would minimize that problem.
How many sheets of plywood is sitting there?
I would like everyone to remember that even with the bus on the ramps, the bus still has the air in the bags. You can see the bus is still in road height, just on ramps. You would feel like you have lots of room under there, your sitting up working on the air dryer and then suddenly you loose all your air. Now you don't have the room you thought.
It is Always a good practice to have the body supported.
Joe, It takes 11 sheets of 3/4" plywood. What Dale said is true, but even with the air bags all the way down, there is still ample room under there to move around and work. In addition to the obvious safety hazzard of having a bus fall on you, I just don't like being in cramped spaces, so it is much better from a psychological standpoint, and they are very stable.
They are heavy. Each ramp is 1' wide and 8' long at the bottom. It takes one under each front axle or two under each rear. I just slip a dolly under them and move them from the workshop to my slab when I am working under the bus. For small jobs, I still use the air/hydraulic jacks.
Dale, you say you are thinking of a pit, but not quite sure for various reasons. Here is another thought, using some facts that you have stated along the way.
You have lots of room.
You are going to pour concrete for your garage.
You don't want to dig a pit for the work involved and that it must be covered to keep rain out.
You like working under the bus on the ramps but it is too much effort to set them up for small jobs.
I suggest make a form and pour concrete ramps outdoors the full length of the bus.
They would always be available and there would be good light all around.
:cool:
Jim, The floor I am pouring will be inside. I had a 40' lean-to that has a top and one side, but has never been completely enclosed and has a dirt floor. Although the existing shed is supposed to be rated at 120 mph, it has been destroyed by the last two hurricanes. I am hoping that enclosing it will keep the majority of the wind out and allow the top to stay on.
I am going to extend the back of the building by 12', pour a concrete floor and completely enclose it. That will give me a building that is 52' X 15' and 13' tall on the low side. I am also pouring an 8'X15' concrete apron at the entrance to the building, just so I don't run directly off the dirt into the building. I decided a picture would be better than a description, so I attached a couple. In the picture you can see a 12' batter board for the building extension and then the 8' board that has a little incline for the apron.
I do actually like being outside when working on the bus, so I am not sure if I want to dig the pit, although it would have distinct advantages. I have to make a decision about the pit very soon. If I dig it, it will only be about 25' long, 2' wide and 4' deep.
As the 2nd pictures shows, I have started grading the area. Notice that one of the 4" extruded aluminum posts is missing on the side of the shed. I got a little close to it yesterday with the box blade. I am also expecting some engineering challenges with making the top come out exactly as I want it without it leaking. I want to use 3' metal roofing instead of the 1' trays that are now on the lean-to.
Dale,
Except for something related to the fuel tank the length of the pit need only extend from the back bumper to the front of the drive axle, plus whatever length you want for the steps going down into the pit.
It looks like you can locate the pit so you can back over it, and turn the coach around to access the underside of the front.
Jim's suggestion is valid, except if you need to reef hard on something, such as fighting to get an air dryer element off, there is no substitute for having your feet planted. If you are sitting under the coach you end up with your butt sliding around while you try to apply force to something stubborn.
Now if Paulette will get under the coach with you, maybe she could do the wrenching while you hold her from sliding.
Jon, since I don't have a coach at this time, what would be the minimum length I could get by with based on the parameters you mentioned? I was planning to just turn the bus around when I need to get to the other end.
I'll tell Paulette about your alternate plan if I decide against the pit.
Dale,
From the rear bumper to the front of the drive axle housing is about 15 feet. Add a little length for steps to go down into the pit and that should work as the minimum.
Thanks Jon. I assume 20' should be ample space.