Getting the air on Heating and cooling, different loads and jobs all considered when it comes to rubber
There’s one component that you can add to your new $500,000 tractor that’s absolutely free and ensures optimal performance.
However, air also has the power to ruin the machine’s performance and cause serious damage.
Correct tire inflation can make the difference between a poor handling, high maintenance machine and a dream machine that lives up to advertising claims, according to two of North America’s leading ag tire specialists.
Andrea Masella is the Trelleborg ag tire marketing manager for North and Central America. James Crouch holds the parallel position over at Michelin.
While the two may be fierce competitors in the marketplace, they agree that farmers can get more performance from their equipment if they closely monitor and manage tire pressures.
Masella said it starts at the factory, where tires are often grossly over-inflated to make the machine more stable on flatbed rail cars and semi trucks during transit. He said this practice applies not only to tractors, but to any implement shipped with mounted tires.
“I’ve seen tires on brand new machines with 50 and 55 p.s.i. from the factory. And they get through the dealership that way with nobody noticing it,” says Masella.
“When the technician prepares the machine for the farmer, he checks hoses, belts, electronics, hydraulics, steering, everything.
“But so often they forget about the tires. They look fine, so why check them? Then the farmer takes delivery and why should he think he needs to check the tires. Of course he assumes everything is ready to go and it should be.”
Masella says the very first thing the operator will notice is vibration. If that doesn’t tip him off about a tire problem, the next clue shows up later with uneven and premature tire wear.
By that point, most people have determined there’s a problem and have adjusted their tire pressures according to the guidelines in the manual. If not, the shaking gets worse and then things start to break.
“It’s exponential. The tractor wears out faster than it should. It leads to broken axles and transmissions,” said Masella.
“I’ve seen many situations where a transmission doesn’t function the way it’s supposed to, so they have technicians working on the transmission. But it turns out tire pressure was too high on one side and too low on the other side. We fix the transmission by adjusting tire pressure. So simple.”
Masella said he was called to a problem tractor on Nicaragua’s largest sugar cane plantation in May. The operator was having major problems pulling tillage and fertilizer application equipment with a new John Deere 7820 210 h.p. tractor.
“I could see right away the weight balance was all wrong. If you’re using the tractor for high torque pulling, then you need 132 to 154 lb. per one horsepower on the tractor. High torque pulling is a plow or cultivation or seeding equipment,” he said.
“But for low torque pulling, you only should have 110 lb. per one horsepower on the tractor. Low torque is pulling a wagon or anything that just rolls along the surface.”
Masella said Trelleborg, as well as all other ag tire manufacturers, publish guidelines that cover tractor weight and power, soil conditions, type of work being performed, speed and other factors. He said the guidelines ask whether you are aiming for traction or flotation, two opposite factors.
“Most people don’t understand that flotation and traction go in opposite directions on the charts,” he said.
“If you adjust for better flotation, you will lose traction. If you go for traction, you will lose flotation. Those two factors always go opposite ways. That’s why you need to work with the guidelines if you want your tractor setup right.”
Masella says Trelleborg has just released a universal load calculator that can be accessed free from any iPhone, iPad, Android or smart phone.
The calculator adjusts for any soil condition, any tractor and any brand of ag tire, not just Trelleborg. It enables precise calculation of a tractor’s load per axle to determine the optimal tire inflation for specific farming operations.
“Here’s one thing I always do when setting up tires. It’s better for ag tires to be slightly over-inflated than under-inflated. The pressure gauge you’re working with may not always be correct, so I always add just a couple extra pounds to be on the safe side.
“But everything is a tradeoff. If you add too much extra pressure, you have a smaller footprint on the ground. You always want five lugs on the ground.”
One of the examples Masella uses when conducting workshops for dealers and farmers is a typical TM600 480/80R50 159D.
In the first situation, the tire is over-inflated to nearly 35 p.s.i., as if it had just been shipped on a new tractor from the factory. At that pressure, the tire has a footprint of 279 sq. inches and it exerts 57.8 p.s.i. pressure on the soil.
In the second situation, the tire is properly inflated to 11.6 p.s.i., as recommended by the load calculator. The footprint now grows to 400.4 sq. inches and the weight on the soil drops to 38.4 p.s.i.
Masella said the over-inflation scenario may seem like an exaggeration, but it happens all the time.
He emphasized that if there was that much variation between tires on the same machine, the traction difference would put phenomenal stress on the entire drive system. Tires with better traction would be trying to do all the work of pulling the load, while over-inflated tires would be trying to spin.
Crouch said tire management is a time-consuming chore that a lot of people rush through. He said central inflation systems can help farmers do a better job of farming without spending as much time babysitting tires.
“There’s a big place for central inflation systems with implements that go between field and road a lot,” said Crouch.
“I’m thinking about the primary tires on planters and air drills, and also tender carts, grain carts, things like that. Implements that need 90 p.s.i. in transport, but nobody takes the time to drop those pressures down when they get to the field.”
Crouch said central inflation is also a smart idea for farmers who often experience a seeding or planting season that extends beyond a couple weeks.
“There’s enough temperature fluctuation in most guy’s seeding season to merit checking the pressures.”
He said for every 3.7 C change in temperature, the tire pressure changes one p.s.i.
Crouch says it’s not unrealistic to start seeding when it’s (4.5 C) and finished when it’s (32 to 37 C), in which case the tires on a row crop tractor may have increased pressure of six p.s.i.
“Managing tires is a year-round job, not just in the summer months. Imagine mounting up a set of new tires on your 4×4 in the fall and pumping them up to eight or 10 p.s.i. on a nice 70 degree day.”
“After your fall servicing is done, you park the tractor in the shed and eventually head down to Phoenix. Meanwhile, the temperature back home drops to minus 40, your 10 p.s.i. drops to (-10 C) and your tractor is resting on the beads.
“I wouldn’t ever go above the recommended maximum pressure for the tire, but I would go that high. And of course start letting pressure out in the spring as soon as the temperature starts to rise. Yes, managing tires is a year round job.”
Crouch said Michelin recently released a set of three recommendations dealing tire management.
Over-inflation: Over-inflated tires cause excessive soil compaction that harms healthy root development, as well as result in a less comfortable ride due to bouncing and vibration. Too much air pressure also increases the amount of tire slippage, causing excess fuel consumption and excessive wear on tires and machine.
Under-inflation: Under-inflated tires can lead to irreversible damage to tire casings, tire failure, excessive wear during road travel and difficulty in manoeuvring at field speeds.
Tire tread: It’s recommended that farmers check their tire tread at the start of the growing season. Make sure tread will last the whole season. Operating on worn tread causes lack of traction, reduces fuel efficiency and increases tire slippage.
Contact Masella at 330-396-7130 or visit www.trelleborg.com/wheelsystems. Contact Crouch at 864-458-4330 or visit www.michelinag.com.