I operate a Cat 14G doing county road maintinace. The machine is a 1993 with 9700 hrs. on it. I have about 2500 hrs on this machine but have serveral thousand hrs on many different kinds of machinary, dozers, backhoe, loaders, etc. Also some time as a macahnic.{sp?} So I have some idea of what I'm doing. But every dog can learn new tricks right. Now for my question? Since getting a new set of tires about 600 hrs ago my blade seems to bounce and/or duck walk at anything over 2nd gear. Not that big of a deal in the summer when reworking gravel roads, but plowing snow in 5th gear it is becoming a big deal, rough roads, time consuming, having to slow down or stop to get boucing to stop. Barn door to barn door is 145 miles, 12 hrs. for me on a snow day. So I have tried several things like adjusting tire pressure, replacing molboard bushings, and other things, but I would like to hear other ideas anything might help. I have talked to tire distibiter and he swears that you can't have a out of round tire on modern day tire manifacture process? Anyways THANKS, any ideas my back will appericate!!
we have a couple of rubber tire loaders that I swear the rear tires are shape like eggs. But it falls on deaf ears... I think there chinese ... no surprise there
i had a tire on a car that had a "radial imbalance'. dont ask me, never heard it before either, but the old guy at the tire shop simpley just moved it to different side and it smoothed right out. never had a problem again these were new tires, re balanced SEVERAL times, checked the drive shaft and any other thing we could thing of. cost me a small fortune. i was lucky to find an oldtimer like this. so, you cant tell me that never happens in todays manufacturing. you tires wouldnt be firestone by chance?
The only way to know for sure is to check your tires run-out. We had a set of Goodyears that drove the operator nuts....The only thing we could do was to find the offending tire and stick it to the front and adjust pressures in an "X" configuration. These tires you are talking about, they are not recaps, are they ?
the tires are on rubber tire backhoes not loaders.. we use to set a block next to the tires on trailers and spin them to see if we had the wheel on straight. Cant think of the name of the wheels, but it's the one that uses the nut and wedges. No OUT OF ROUND TIRES is BS .... nothing is perfect, why do you think they have to balance them... They're not perfect.... If nothing else call the customer service for the tire manufacturer
U can try something with tyre pressure on your tandems , richt for and left after 24 psi and left for and richt after 22 psi .
Tire manufacture is Continetal. I think it says on tire that it is a product of Check Repubic? They look like Michlen snowplus. I just finished building a jig yesterday to measure tire run out but haven't time to use it. I have been working with tire pressures with no success for a long time, that was tire guys suggestion to try 10lb. pressure offset in X pattern, then reverse pattern to see if it changes anything. I've tried to measure circumfurence to tire, with as much as 2 1/4 in. difference but my method to measure my not be very accurate? Would that be enough to cause problems. The bounce is pretty good, probaly 4 to 6 in. at 10 to 12 MPH.
We run Michlen Snow Plus on one 140H (02) and Bridgestone Vtech on the (07) 140H. Over the years we tried most everything and nothing really worked but we run 42 lbs in the rear tires and 35 lbs in the front. This seems to work the best for us. Another person will tell you something else but it depends on conditions and other things. Also speed. If in a higher speed try shifting up and throttle back, make it work some and that might help. Or speed upa little. Hope some of idea's help. Different tire brands also act different.
:usa:usaTire pressure in a grader is usually a machine to machine approach, being like graders are like women, everyone is different. The 10lb variance in the x pattern is the first attempt I would make to try and fix the problem. This is time consuming but the cheapest attempt. This is going to sound absolutely crazy to you but the next test I would do is to try and back the grader up in a perfectly straight line. If your machine is kinda hard to back up perfectly straight then I would cut two to three inches out of the stabalizer (tie bar) on the front end. I know this sounds absoultly crazy, but the processes has almost always taken about 95 percent of the bounce out and your grader will be a completely different handleing machine.Hope this helps you out.
Grandpa, do you have pictures of what and where you shortened that tie bar? Sounds very interesting!
Grandpa: Interesting thing to do, and i'm not against trying this. If only to keep from wearing outsides of front tires down. Could you give me a more detailed explaintion of what it will do to the way my blade will act? And why you think it may help?
It's all in the details. It really appears at first glance that you answered your own question to some degree. PHP: Since getting a new set of tires about 600 hrs ago Motor Grader bounce is thought by many to be one of the most confusing and complex problems to solve, but it’s really simple in some respects. Due to gravity nearly everything on planet Earth has a frequency at which it will resinate/bounce. The motor grader is a mass sitting on six springs/pressure vessels. The larger the spring the lower the frequency at, which the mass will bounce. This is why we own two sets of rims and tires for each one of our motor graders. You didn’t give a lot of details or specifics about your 14G, but I can tell you this; there is a huge difference in how the machine is equipped and at, which speed/tandem phasing that machine/mass likes to bounce/resinate easily. Example: the base weight on a 93 14G was close to 40,000lbs., my own 93 14G weighed about 52,500lbs due to the optional equipment. The 14H I ran after that had a summer time weight of nearly the same, but a wintertime weight pushing over 56,000lbs. Just changing the tires and rims; wide base 20.5-R25 vs standard 16:00R25 made a couple thousand pounds difference and the change was all well below the center of gravity on the machine. The speed at, which I could safely due gravel road maintenance with the 16:00 tires was different than the speed with the 20.5R25. 16:00s perform okay on a base machine, but when you start hanging 3500lbs of ripper, additional shanks, Pewag All Square tire chains, Kennemetal tool Bars, Pushblocks, Longer Moldboards they start to hop like a rabbit and with the wrong moldboard angle they walk like a duck. Just because something looks or appears similar means nothing! It’s the details and manufacture quality control that counts. Rather than bash a certain brand I’ll just say I’m a huge Michelin wide base radial fan (X Snowplus and XHA). I’ve also had great performance from Bridgestone tires; we use both their snow-wedge (VSW) tires and the wide base VMT. For the record we have had to replace brand new rims, which were out of round and shave some tires at times to get them riding right. I use a dial indicator on a magnetic base to check runout. I mount it on the tandem case. Even with good tires every grader i've ever operated has a speed at, which it loves to bounce, but I personally believe the 2nd most important item to understand in this phenomenon is that it takes some form of input to get it started. This where leaning wheel, windrow alignment, moldboard angle, drawbar angle, articulation, etc. etc. all can be used to eliminate that FIRST input, that first bounce. Because once it gets started it's like riding a bicycle with a boot mounted on the rear tire, it just keeps kicking you in the rear to remind you that you screwed up. :Banghead Good Luck….Randy
Yep Randy K. That is what I'm looking for the cause of the first small bouce. I'm possitive that it is tires, and have been trying to get my hands on a dail indicator, with out buying one. Working for a county goverment with a small repair budget the tires will not be replaced, nor is it likely tire distribtor will help. Just looking for ideas and imput from different people to see if I've missed something or a possible way to reduce problem. Thanks for ideas already recieved.
Makes good sense grandpa..I've had many different brands of tires over the years..some bounced, some didn't. I've tried the x pattern, adjusting up and down..tried very damn thing. I think it just depends on what kind of tires you get..really. By the way..Merry Christmas to ya buddy!
yep, thats the money post right there.
Get the Best out of your tires To make your tires do the best you will have to make some changes/rotations.... You don't have to have anything fancy to check your tires "out of round & runout". 1) First get the rear tires off the ground. 2) Get some wood blocks and markers 3) Turn the rear tires VERY slowly. 4) Mark the high spots on each tire; take marker and straight edge "wood/steel" bar, secure one end and keep moving it until it just touches the tire, mark tire. 5) Mark the nearest spot of the sidewall/tread to the grader, IE above. 6) You can use paint or permanent marker; transfer the spots to the wheels "use different color for out or round & runout. 7) Now the work begins; the idea is to offset the tires for the front one is just the opposite of the rear tire. Do this to both sides. 8) Road/Grade test. 9) If ride is not good enough you will have to rotate one tire and try again. Recommendations: Keep a written record of what you have done as you progress; Use the valve stems on each tire as the base line for each tire. My experience you should be able to get the best performance with about 3 or 4 adjustments. It may never be great but, you can make it MUCH better....
Wow! great information buggyman. Very detailed..thanks! I say.. let er bounce..you get used to it after awhile..lol. Helpful ain't I?
Grader4me is rite, it makes speed bumps to slow people down.
All I have is a old 12E and the bounce well I thought it was an extra we got from new!
I have found that air pressure makes a differents. I carried 40 pounds in the front, 45 in the rear all year around, for plowing with a wing 50 on the wing side. I also plowed in 7th gear at 1900 rpm anything over seemed to want to bounce. I find that 5th & 6th were terrible for bouncing. I also powering up to 1900rpm slowly seems to help with bouncing. When blading gravel I bladed in 3rd or 4th, the lighter the load on the blade the more I tilted the blade forward to make the work harder. Duck walking and bouncing can be a real pain, sometimes you just have to try different things to help get it right.
Randy gave very good technical advice. I'm betting it's your tires. Over the past twenty years I've had two sets of tires that bounced, nothing fixed it except replacing the tires, both sets were Firestone Bias Ply. My current grader is on 17.5 Micheln Radials. I absolutely can't push snow in fifth gear, must either use fourth or sixth. I prefer sixth, 7.2 mph, very rarely bounces and then only when on a hill and the speed drops into the 6 mph range. Sadly, in your case you can't seem to find anything other than snail pace that works. Been there, that really sucks. In the governmental world that you and I live in, it's hard to sell them on a new set of tires when there's nothing wrong with the ones you have. And none operators always say go slower, but get my road cleared first.
put wheel balancing powder(bags) in tires .its for trucks ,but works fine in graders tires at higher speeds.