|All photos with blue borders expand if clicked|
This Champion 760 is not our first grader, but it is the biggest. In the beginning (or our grader days) we had a Cat #12 (about a 1945 model of the famous 'finger slapper' variety). They were called 'finger slappers' because the blade was controlled by a series of levers that looked like hydraulic control levers but which in fact engaged 'jam gears' or what we call 'dog clutches'. Basically, you moved the blade by jamming the right set of gears together which would connect engine power to the proper rack and pinion so as to move the blade. If the operator failed to firmly engage the dog clutch, the gears would slip and the lever would flop violently--slapping your fingers or anything else in the way. Anyhow, something over 20 years of finger slapping and the time came for bigger and better, and this Champion 760 joined our stable. Champion is a domestic Canadian brand of grader and as you might guess, we imported it from Calgary, Alberta. Nothing special against Cat, its just that used Champions sell for a song compared to Cat Graders.
It seems that there are graders and then there are graders. The vast majority of all graders in the world look very similar to one another from a distance. The Champion is no exception. Six wheels with a tandem rear drive is very typical of all graders and has been almost a standard way of making a grader since the 1930's. The tandem drive reduces the amount of blade movement as a result of a tire 'running over something'. Beyond the fact that most (but not all) graders have 6 tires there are a lot of subtle differences. In most instances, for example the rear wheels will be powered from a single drive axle by roller chains running in an oil bath 'chain box' which also serves as the walking beam. However, there is a great variance as to what the front wheels do. Some graders have a mechanical front wheel drive, some a hydraulic drive, and probably the majority, no front wheel drive at all. Most will have a front wheel, 'wheel lean' allowing you to lean into your work a bit and compensate for the side torque caused by the blade.
Competitive brands of graders (anything but a Cat) have used fully hydraulic blade controls for years and this Champion is no exception. The trendy innovation in graders (featured by Cat for the last 20 years) is the articulated frame design. It is not present on this Champion. An articulated frame model with have a hinge in the frame behind the cab and in front of the rear tires and engine. This additional steering joint makes it easier to get 'behind' your work which you never can quite do with a straight frame model.
Beyond articulation, the only major innovation in road graders in the last 50 years has been the inclusion of a power shift transmission in favor of a classic manual shift. As you might guess this Champion has the classic manual shift transmission which is just fine for a maintenance operation because its potential repair bill is a whole lot less than that of a power shifted box.
The next subtle difference you will find in road graders involves both size and horsepower to weight ratios. The 'size' of a grader is often classed by the blade length. As you might have suspected the standard blade length on a Cat # 12 was 12 feet which means that when placed in a grading position of about a 60 degree angle it would grade approximately 8 feet wide. Intermediate sized graders will have a 14 foot blade. which is what this Champion has. The next issue is simply horsepower. If you are going to use a grader for road construction, you want a very heavy and powerful grader which will push large blades of heavy material. It needs to be heavy for strength and traction. If you are hassling chuckholes on a county road, extra power and weight mostly mean more fuel consumption. My old #12 weighed 20,000 lbs and had a 100 horsepower. It would scratch gravel around a chuckhole just as well as this Champion which weighs 40,000 lbs and has 200 horsepower. The engine in this hummer is in fact a Detroit 6-71N, which by all standards is big power for a grader of this class. But guess which grader will do a better job (faster-quicker) of spreading a 20 yard pile of Pit rock? No competition here! Finally, there is the Snow plow grader. Well guess what, they never made a grader that had too much power or went too fast to plow snow. A slow grader won't plow snow at all. The blade on a grader is not optimally shaped for plowing snow, and unless you can attain a good speed the snow won't scour. It will simply pile up in front of the blade until you can't push it and there you are. Accordingly, if you have snow plowing in mind when thinking of a grader, a light grader with a big engine comes to mind. If you can just get the grader going fast enough, you can bury everybodies mailbox!
If you are looking for Champion graders these days you won't find the company. They sold out to Volvo and the product is marketed under the Volvo name.
Since graders are associated with road work, and roads in come climates accumulate snow, it is not beyond the pale to think of using your grader for snow removal. You can either specially set up the grader for snow work or use grader as it comes.
One thing that you will almost certainly want to consider is the addition of tire chains. Now turns a road grader into a large sled. Now understand that graders are made for traction. All four wheels on this model are locked together. There is no differential. The driving wheels will all turn, but also understand that it behaves therefore just like a car with posi-traction---When it spins it goes sideways as rapidly as it goes forward. If you are on the flat perhaps this makes no difference, but if there is a canyon over there it is perhaps significant. It's been said that one should not grade the should of a road when the road has no shoulder. The same applies to plowing snow---don't drive where there is no place to drive....
The photos on the left show a typical tire chain, and a close up of the connector. This particular set of chains has tie bars in it between the cross bars to control sideways sliding. They are not universal and perhaps are overkill. You install the chains just like you might on a auto or truck---throw the chain over the tire, then drive forward, hook up the ends, then drive some more and tighten them up. Unlike a car there are no fenders in the way, but the chains are fairly heavy.
Once the chains are on you are ready to go. You will plow with the blade rolled all the way back. As with dirt grading you will rotate the blade until the snow moves down the blade to the side because if you have the blade too straight the snow will just pile up umder the circle until you can't push it any more. A fairly aggressive speed improves performance. The snow will scour better and fly off the the road farther. This is why a light powerful grader is popular for snow work.
If you are real serious about snow work with a grader there are attachments to enhance the snow work. As you can see from the photos at the top of the page, this grader is set up for but not equipped with a front blade. Either a V-plow or an angle snow blade of the type commonly seen on the front of snowplow trucks can be attached to the front. Additionally a 'snow wing' can be added to the right side. A short cab high boom is attached to the frame behind the cab and a folding blade is hung from it when lowered angles out to the right side for additional blading width.
|Brake repair sequence|
The technology of road graders has developed to the point that regardless of the brand of grader that you have, its basic operation will be approximately the same. While older graders have power assist mechanical controls for the blade and newer ones have hydraulics, the functions are the same. Almost without exception the grader will be configured with the engine on the back over a tandem drive. The wheels are driven by roller chains running in oil in chain boxes which also serve as walking beams. Many graders do not even have a differential, so all 4 rear wheels are locked together and must slide when you turn. Articulated graders typically have a differential in them because they will turn shorter.
The front grader frame will be arched over the blade and the blade circle will be attached with a giant ball and socket joint just above the front axle. The pulling power of the grader will be passed through that connection. A sturdy steel beam will extend backwards to the circle on which the blade is mounted. The basic functions of the grader blade are as follows:
The latter two functions have always appeared on graders but on older graders were set manually (as in with wrenches). Of all these controls the most used will be the blade lift/drop. There is a separate control for raising and lowering each end of the blade. To lift the blade it takes both hands on for each end of the blade. The steering wheel generally takes care of itself, or if necessary you can steady it with your knee. In the Classic Cat configuration (also emulated by Champion) these levers will be the 3rd out from the middle. The two middle levers will typically control the blade rotate, and the circle shift. These will be used to set up the grading operation but are little used on the fly. The Rotate is not only used to determine whether you are going to cast left or right, but also depending on the activity it is also used to set the angle of the cast. For example, if you are doing heavy cutting you will put a fairly severe angle on the blade say 45 degrees or more, but if you are spreading gravel a straighter angle of around 30 degrees works better. If you are plowing snow, you will adjust the angle of the blade so that the snow ill scour. If you have never run a grader or pulled a plow, you probably don't know what 'scour' means but once you have you will understand. If you set the blade too straight, the snow just piles up in front of the blade until you can't push the pile anymore and you are stopped. With adequate angle, the snow will slide down the blade, and if you are going fast enough, fly clear off the road.
The circle shift is a control that moves the entire blade 'circle' to the left or right. This assists in getting the blade out beside you which is particularly helpful if you are dressing up a road shoulder, because you can keep the grader on the firm part of the road and move the whole circle off to the side. Often with some manual adjustments the blade can be turned clear out from under the grader and rotated vertically for sloping banks. Most graders will extend the blade circle further to one side than the other, and have a reversible linkage in the circle shift to allow a choice of which way the blade will extend the most. Customarily, graders are configured to extend the blade out further to the right than to the left. This is called a 'right hand grader'. The reason is of course that graders doing highway work generally work on the right side of the road.
The final two functions on the blade are the blade side shift and blade tilt. As noted before these functions are nearly always present, but in older graders required manual settings. As the name implies, the side shift slides the blade endwise under the circle. For example, if you want to reach way out to the right, you can use the circle shift to move the circle to the right, and then increase the reach still further by sliding the blade to the right. Often these two functions together will effectively get about half the length of the blade outside the tires. The side shift is also necessary when configuring for bank sloping. The blade tilt rotates the blade on its axis forward. The grader blade is normally heavily curved and the cutter bit sticks forward at a fairly sharp angle. In theory the material picked up by the blade will roll as it scours down the blade. The blade tilt will roll the blade forward so that the cutter bit sticks almost straight down. This is useful for scratching gravel where you don't want to cut into the roadway.
Most graders will have two additional controls in the string of levers. By custom these will be just inside the blade lift levers. On the right will be the wheel lean, and on the left will be the scarifier, though the location of the latter is not sacred. Though not a blade control, the wheel lean is critical to the operation of the grader. The grading operation necessarily creates major side torque on the machine. The blade angle is always trying to push the grader sideways. You compensate for this by leaning the front wheels into your work. This gives the tires a firmer footing and neutralizes the side torque, making the machine much easier to control.
Newer graders articulate as well, meaning that they have a hinge in the main frame between the cab and the engine which improves the ability of the grader to maneuver. Older graders will usually be found with a manual shift, while the newer models will have a power shift, but generally, the power shift will be without a torque converter, as the latter makes the speed hard to control under variable loading conditions. In any event, a wide variety of speeds are usually provided ranging from a 'creeper gear' to a high gear in the 25 MPH range. Unlike many pieces of heavy machinery, graders are quite 'driveable' and often range many miles from their "home" during routine use. Newer models have large automotive style brakes, and many of the features of a highway vehicle such as lights, turn signals, rear view mirrors, windshield wipers, heaters, air conditioning, adjustable seat, etc. Likewise enclosed cabs are almost a given and have been for over 50 years. The reason for this is that graders are almost always pressed into service in the snow zones for snow removal and other inclement weather service.
Another operation that you will almost surely need to be able to do if you run a grader is that of 'pulling a ditch'. Ditching with a grader requires a bit of guts as to do it right you have to get in with your work. Assuming you are ditching on the right, shift the circle to the right and rotate the blade so the leading edge of the blade is near the front tire. Operate the side shift as necessary to slide the blade forward so the rear end of the blade will clear the rear tires. The length of the blade and the size of the grader will dictate just how you configure it. A grader with a 12 foot blade will often be able to rotate the blade to almost any configuration without hitting the tires, but longer blades such as the popular 14 foot blade will require some care to avoid hitting the tires.
With the circle to the right and the blade rotated around and side shifted forward, the front end of the blade should be just to the outside of the front tire and the rear of the blade about centered under the machine. Now, keeping the left side of the blade high under the machine lower the front of the blade with the right blade lift lever and proceed. You are very nearly pushing on the end of the blade and the machine will cut through amazing hard material in this configuration. Lean your wheels to the left and drive in the ditch. The further to the right you move the circle and the straighter on you get the blade the narrower the ditch will be. If you have particularly hard materials you can even swing the blade in behind the front tire and run the front tire up on the bank outside of the ditch. Tires are expensive for watch for blade conflicts with both the front and rear tires, but as you rotate the blade inward you turn the blade into a knife slicing with the end of it instead of scraping with the side of it. This will allow you to slice through many varieties of softer rock that even a bulldozer might struggle some with. The dirt will window row up under the grader and must be scraped across the road. in a subsequent passes. The proper size for the ditch is of course another matter. There are lots of reasons for various sizes depending on what you are trying to accomplish. Large deep ditches last longer, but are more of a hazard to stray vehicles that wander into them. One thing, to be sure, is to get out of the grader once in a while and look at your work from the ground. If you just keep ditching deeper until you have trouble sitting in the seat on the grader without falling out, you will find that the ditch is about 3 feet deep or more, which might not be what you had in mind.
Issues that take a little for thought include digging a ditch that ultimately empties into a canyon. the problem here is that your front wheel leads the blade so it arrives at the cliff before the blade does making the last few feet of the ditch an experience. Likewise, you can do a lot of damage to existing culverts while cruising down a ditch and ditto for those ever present buried utilities that are suppose to be 30 inches below the bottom of the ditch.
Ditching in the rain has its advantages because you don't need a surveyor to see if the ditch is going to take water or not, but it is also a glorious way to get stuck, and 40,000 lbs of iron buried in about 3 feet of mud is not easily retrieved.
There is, of course, considerable disagreement on how wide a logging road should be especially on public lands. The marijuana growers association opposes all roads because it makes it too easy for the cops to get in and the U.S. Forest service is thinking of having a road suitable for tourists after the logging is done, and the logger wants a road, but no more than he needs for his equipment so everyone has a different vision of the 'correct width'. Absent political interference, though 16 foot roads on a 20-24 foot right of way make reasonable sense. Logging machinery tends to be up to 12 feet wide with only extraordinary pieces being over 14 feet wide so getting down such a road will usually be possible. Also this sort of a width permits the narrower highway trucks to vary their path considerably and avoid rutting the road by 'driving all over it'. Mainlines, of course, tend properly to be wider than spur roads, with log truckers almost universally using CB radios as traffic control devices so they can avoid meeting one another in pinch points.
Enough said about that, my point is this: The Champion 760 is a real grader in anybodies book and if you meet it face to face, best you let it play on though, because it is big, heavy and powerful. So heavy and powerful, in fact, that it runs on 16x24 tires instead of the more standard 14x24 grader tires. The machine exceeds the weight appropriate for the smaller size, and if you need some of these larger tires, don't expect your local friendly tire shop to have a large selection to choose from. We just special ordered a set all the way from Israel, of all places, and it took about 90 days to get them.
|Komatsu 825 w/ ripper|
Another trend in graders over the years has been toward providing a ripper on the back of the machine. Graders for half a century have had what is known as a scarifier mounted forward of the blade and usually behind the front wheels. It primary use was to dig a little gravel loose so you could rearrange the chuckholes on a gravel road, but in recent years, particularly with the trend toward larger graders you see rear mounted rippers. A typical one shown here on a large Komatsu grader should make it clear that their use is more than scratching potholes out of gravel roads. A century ago when farmers were building roads with horses they used generally 2 horse drawn tools. First they would 'plow', not with a plow as invented by John Deere, but really just with a pointed stick to loosen the soil, and then they would use a fresno which sort of looked like a wheel borrow with no wheel and the front cut out of it. By raising or lowering the handle bars the operator could control whether the front cut into the ground or slide along the ground as it was pulled by the horse.
Well, not much is changed. when there is a road to build now that has some serious dirt moving, one of these large graders with a ripper can be used to peel the dirt loose. It can then be windowed with the blade, and then easily loaded in a 'scraper', 'can' or 'pan' depending on what part of the country you are in. The scraper, of course, is just a motorized fresno powered by large diesel engines and riding on large rubber tires but the concept is the same.
|Cat 16G Grader|
I haven't mentioned them, but there is also a 'supergrader' class out there. These very rare machines are considerably larger than even this 760, and sport blades from 16 to 20 feet wide. They are great for building airports, and maintaining haul roads in mining operations, but are a little much for logging roads which tend to be a single track road rocked around 16 feet wide. The Cat 16 is in this class, though of late they have outdone themselves with a Cat 24. This latter model weighs 65 tons, has 500 hp, a 24 foot blade and sells of roughly a million dollars U.S. The Cat 16 has historically sort of been a D-8 on rubber tires, and the 24 is pretty much a D-10 on rubber tires. You won't find one of these pulling a ditch along the local county road which is probably just as well as they could wipe out the mai boxes on both sides of the road at once.
Big yellow machines don't last for ever, and they do need repairs from time to time. For a number of reasons graders have a fairly long life span. One reason, of course, is that they tend to be not used every day. With a working speed of over 5 M.P.H. you can visit a lot of road in a day. Two or three passes is about as much good as you can do for any road which implies that the capacity of a grader is a whale of a lot of road. The construction class graders, of course, will do more than scratch gravel but even when the task is spreading "Pit Run" rock, a couple passes behind a window belly dump does the job. Even with this, however, you learn right away that 'faster with a light cut' works better than slower with a heavy cut.
As with any machine, though, repairing the Champion takes some special tools and determination. The brakes are 4-wheel hydraulic with a power assist. The wheels are spoke wheels that attach with clips. The rear hub is a once piece unit which comprises the brake drum and hub. It is on a tapered and keyed spindle. To service the brakes you have to pull the hub which is not easy task. I've been there, done it. The 3 -1/2" spindle nut seems to respond well to a 1-1/2" drive impact wrench or a double compound (Multiple planetary reducers are stacked on one another allowing a 200 lbs man with a 3 foot wrench to emulate the force of a 12-15 foot long wrench). The hub, itself has a couple 1' puller bolt holes to which you fasten your handy andy 100 ton portapower and pull. Be sure and use quality bolts, because soft bolts won't hold these kind of stresses. My experience with soft bolts is that at around 40-50 tons they began to stretch and fail. Being more sophisticated the second time around, I used a par of grade 5 bolts (3 strikes on the head) and these proved sufficient though the hub came loose and something less than maximum effort with the 100 ton jack. We actually got it, at around 60 tons of force with a sledge hammer assistance. Once the brake drum is pulled the brake repair is very familiar--a couple brake shoes, some springs, and a single 1 - 1/4" wheel cylinder.
While I am talking about repairs, one other thing to particularly watch out for is broken stud bolts which are used to hold the wheels on. The front wheels in particular have the potential for tremendous lateral stress, and a couple of missing wheel clips together is a front wheel waiting to pop off when you least want it to.
|note crack in tire|
Although we didn't buy our tires there, you can read all about grader tires as made by Bridgestone/Firestone by looking at their web site. They even have technical bulletin on dealing with 'loping" which is a problem that you have with a grader under certain conditions. "Loping" refers to the habit of heavy equipment to start bouncing up and down on its big rubber tires as the speed increases. This is obviously a problem if you are trying to keep your blade true. It can be a real frustration when plowing snow, as you want to gain maximum speed to enhance the scouring, but increased speed tends to make the grader behave like a basketball going down court which is a problem. It not only makes the machine hard to control, it is simply impossible to maintain proper blade clearance (from the road) if the whole machine is dribbling down the road.
Because all the drive tires are locked together, the drive tires take quite a bit of abuse. Shown here is a tire about to fail. You can see that the casing is broken diagonally most of the way across the tire and the tube is showing. It's tire for replacement.
Dismounting the tires can be a challenge, but we have made a press to help with the project: See Tire press
Completed some of the most extensive repairs on the grader in years. Dismounted the left front driver and had a aboot put in it because of about a 2" break in the casing. This are 12 ply tires (light weight) and I suspect they will need replacing soon. The left rear wheel cylinder was leaking so I decided to give it a left side brake job, as the steel lines running to the wheel cylinders have been an issue. We had replaced the wheel cylinder line to the left front driver just before I last used it, and the bleeder screws were rusted down. I took off both tires and pulled the brake drums off. I found 1 shoe with broken/missing lining in each wheel. We had the shoes relined and rebuilt both wheel cylinders, and replaced the bleeder screws. The rebuild kit is a Wagner F3505. The brakes are suppose to be auto adjusting but all that stuff was rusted down. Anyhow, the grader now has brakes.